Date | Change |
| 40 | Diocese of Taormina was established |
| 42 | Diocese of Catania was established |
| 50 | Papal See of Roma was established |
| 100 | Diocese of Agrigento was established |
| 100 | Diocese of Benevento was established |
| 100 | Diocese of Napoli was established |
| 100 | Diocese of Nepi was established |
| 100 | Diocese of Palermo was established |
| 100 | Diocese of Pozzuoli was established |
| 100 | Diocese of Spoleto was established (without ecclesiastical province) |
| 100 | Diocese of Thurio was established |
| 100 | Diocese of Tricala was established |
| 100 | Diocese of Vescovìo was established |
| 140 | Diocese of Terni was established |
| 200 | Diocese of Aquileia was established |
| 200 | Diocese of Capua was established |
| 200 | Diocese of Forlì was established |
| 200 | Diocese of Milano (Ambrosian Rite) was established |
| 200 | Diocese of Nola was established |
| 200 | Diocese of Ostia was established (became suffragan of Roma) |
| 200 | Diocese of Todi was established |
| 200 | Diocese of Tortona was established |
| 200 | Diocese of Trento was established |
| 237 | Diocese of Fondi was established |
| 250 | Diocese of Trani was established |
| 259 | Diocese of Lentini was established |
| 280 | Diocese of Fossombrone was established |
| 300 | Diocese of Amiterno was established |
| 300 | Diocese of Ancona was established |
| 300 | Diocese of Arezzo was established |
| 300 | Diocese of Assisi was established (without ecclesiastical province) |
| 300 | Diocese of Asti was established |
| 300 | Diocese of Bologna was established |
| 300 | Diocese of Cagliari was established |
| 300 | Diocese of Calvi was established |
| 300 | Diocese of Carini was established |
| 300 | Diocese of Chiusi was established (became suffragan of Roma) |
| 300 | Diocese of Civitavecchia was established (without ecclesiastical province) |
| 300 | Diocese of Claterna was established |
| 300 | Diocese of Eca was established |
| 300 | Diocese of Eclena was established |
| 300 | Diocese of Erdonia was established |
| 300 | Diocese of Faenza was established |
| 300 | Diocese of Fermo was established |
| 300 | Diocese of Firenze was established |
| 300 | Diocese of Forlimpopoli was established |
| 300 | Diocese of Formia was established |
| 300 | Diocese of Forum Clodii was established |
| 300 | Diocese of Genova was established |
| 300 | Diocese of Labico was established |
| 300 | Diocese of Lucca was established (without ecclesiastical province) |
| 300 | Diocese of Modena was established |
| 300 | Diocese of Nuceria was established |
| 300 | Diocese of Padova was established |
| 300 | Diocese of Palestrina was established (became suffragan of Roma) |
| 300 | Diocese of Parma was established |
| 300 | Diocese of Pesaro was established (without ecclesiastical province) |
| 300 | Diocese of Pisa was established |
| 300 | Diocese of Pistoia was established |
| 300 | Diocese of Pitinum was established |
| 300 | Diocese of Porto was established (became suffragan of Roma) |
| 300 | Diocese of Ravenna was established |
| 300 | Diocese of Rimini was established (without ecclesiastical province) |
| 300 | Diocese of Septempeda was established |
| 300 | Diocese of Siena was established (became suffragan of Roma) |
| 300 | Diocese of Siracusa was established |
| 300 | Diocese of Sora was established |
| 300 | Diocese of Teano was established |
| 300 | Diocese of Terracina was established (without ecclesiastical province) |
| 300 | Diocese of Torres was established |
| 300 | Diocese of Tre Taverne was established |
| 300 | Diocese of Vercelli was established |
| 300 | Diocese of Verona was established |
| 301 | Diocese of Voghenza was established |
| 308 | Diocese of Sala Consilina was established |
| 312 | Diocese of Grumentum was established |
| 313 | Diocese of Atella was established |
| 313 | Diocese of Liternium was established |
| 323 | Diocese of Acqui was established |
| 323 | Diocese of Aosta was established |
| 326 | Diocese of Albano was established (became suffragan of Roma) |
| 340 | Diocese of Bari was established |
| 340 | Diocese of Canosa was established |
| 350 | Diocese of Albenga was established |
| 350 | Diocese of Brescia was established |
| 350 | Diocese of Imola was established |
| 350 | Diocese of Narni was established |
| 350 | Diocese of Pavia was established |
| 350 | Diocese of Pitinum Merges was established (without ecclesiastical province) |
| 350 | Diocese of Tivoli was established (without ecclesiastical province) |
| 355 | Diocese of Aquileia was promoted as Metropolitan Archdiocese of Aquileia (with suffragan sees Pavia, Poreč, Trento and Verona) |
| 372 | Diocese of Brescello was established (from the suppressed Diocese of Parma) |
| 372 | Diocese of Parma was suppressed (to establish Diocese of Brescello) |
| 374 | Diocese of Lodi was established (became suffragan of Milano) |
| 374 | Diocese of Milano (Ambrosian Rite) was promoted as Metropolitan Archdiocese of Milano (with suffragan sees Acqui, Albenga, Asti, Bologna, Brescia, Faenza, Genova, Lodi, Modena, Tortona, Vercelli and Voghenza) |
| 375 | Diocese of Altino was established |
| 380 | Diocese of Concordia was established (became suffragan of Aquileia) |
| 380 | Diocese of Zuglio was established |
| 386.11.01 | Diocese of Como was established (from Metropolitan Archdiocese of Milano and became suffragan of Milano) |
| 397 | Diocese of Novara was established (became suffragan of Milano) |
| 400 | Diocese of Acerenza was established |
| 400 | Diocese of Alba was established (became suffragan of Milano) |
| 400 | Diocese of Anzio was established |
| 400 | Diocese of Ascoli Piceno was established |
| 400 | Diocese of Bergamo was established (became suffragan of Milano) |
| 400 | Diocese of Bettona was established |
| 400 | Diocese of Bomarzo was established |
| 400 | Diocese of Brindisi was established |
| 400 | Diocese of Castellammare di Stabia was established |
| 400 | Diocese of Caudium was established |
| 400 | Diocese of Celano was established |
| 400 | Diocese of Cingoli was established |
| 400 | Diocese of Cornus was established |
| 400 | Diocese of Egnazia Appula was established |
| 400 | Diocese of Ferento was established |
| 400 | Diocese of Fiesole was established |
| 400 | Diocese of Gubbio was established (without ecclesiastical province) |
| 400 | Diocese of Lilibeo was established |
| 400 | Diocese of Lucera was established |
| 400 | Diocese of Matelica was established |
| 400 | Diocese of Nocera Umbra was established |
| 400 | Diocese of Nomento was established |
| 400 | Diocese of Osimo was established (without ecclesiastical province) |
| 400 | Diocese of Otranto was established |
| 400 | Diocese of Otricoli was established |
| 400 | Diocese of Pesto was established |
| 400 | Diocese of Piacenza was established (became suffragan of Milano) |
| 400 | Diocese of Pitinum was suppressed (to Diocese of Amiterno) |
| 400 | Diocese of Plestia was established |
| 400 | Diocese of Pollentia was established |
| 400 | Diocese of Potenza Picena was established |
| 400 | Diocese of Sarsina was established |
| 400 | Diocese of Siponto was established |
| 400 | Diocese of Squillace was established (without ecclesiastical province) |
| 400 | Diocese of Termini Imerese was established |
| 400 | Diocese of Tharros was established |
| 400 | Diocese of Tolentino was established |
| 400 | Diocese of Torino was established (became suffragan of Milano) |
| 400 | Diocese of Treia was established |
| 400 | Diocese of Treviso was established (became suffragan of Aquileia) |
| 400 | Diocese of Urbisaglia was established |
| 400 | Diocese of Volterra was established |
| 439 | Diocese of Galazia in Campania was established |
| 440 | Diocese of Ivrea was established (became suffragan of Milano) |
| 440 | Diocese of Ravenna was promoted as Metropolitan Archdiocese of Ravenna (with suffragan sees Faenza, Forlì, Imola, Modena and Voghenza) |
| 450 | Diocese of Amelia was established |
| 450 | Diocese of Aquaviva was established |
| 450 | Diocese of Aquino was established |
| 450 | Diocese of Aveia Vestina was established |
| 450 | Diocese of Camerino was established |
| 450 | Diocese of Carmeiano was established |
| 450 | Diocese of Città di Castello was established (without ecclesiastical province) |
| 450 | Diocese of Cremona was established (became suffragan of Milano) |
| 450 | Diocese of Cuma was established |
| 450 | Diocese of Faleri was established |
| 450 | Diocese of Falerone was established |
| 450 | Diocese of Forum claudii was established |
| 450 | Diocese of Gabi was established |
| 450 | Diocese of Gualdo Tadino was established |
| 450 | Diocese of Labico was suppressed (to establish Diocese of Subaugusta) |
| 450 | Diocese of Montecassino was established |
| 450 | Diocese of Ofena was established |
| 450 | Diocese of Reggio Emilia was established (became suffragan of Milano) |
| 450 | Diocese of Salpi was established |
| 450 | Diocese of Sant’Angelo in Vado was established |
| 450 | Diocese of Subaugusta was established (from Papal See of Roma and from the suppressed Diocese of Labico) |
| 450 | Diocese of Sulmona was established |
| 450 | Diocese of Sutri was established |
| 450 | Diocese of Tarquinia was established |
| 450 | Diocese of Tronto was established |
| 450 | Diocese of Valva was established |
| 450 | Diocese of Velletri was established (became suffragan of Roma) |
| 451 | Diocese of Vibo Valentia was established |
| 457 | Diocese of Blera was established |
| 460 | Diocese of Telese was established |
| 465 | Diocese of Luni was established |
| 465 | Diocese of Numana was established |
| 465 | Diocese of Passo Corese was established |
| 480 | Diocese of Anagni was established (without ecclesiastical province) |
| 480 | Diocese of Fano was established |
| 480 | Diocese of Ferentino was established (without ecclesiastical province) |
| 480 | Diocese of Foligno was established (without ecclesiastical province) |
| 480 | Diocese of Lorium was established |
| 480 | Diocese of Venafro was established |
| 484 | Diocese of Cagliari was promoted as Metropolitan Archdiocese of Cagliari (with suffragan sees Tharros and Torres) |
| 484 | Diocese of Forum Traiani was established |
| 484 | Diocese of Sulci was established |
| 490 | Diocese of Alife was established |
| 490 | Diocese of Arna was established |
| 490 | Diocese of Avellino was established |
| 490 | Diocese of Bolsena was established |
| 490 | Diocese of Chieti was established |
| 490 | Diocese of Minturno was established |
| 490 | Diocese of Norcia was established |
| 490 | Diocese of Perugia was established |
| 490 | Diocese of Populonia was established |
| 490 | Diocese of Potenza was established |
| 490 | Diocese of Roselle was established |
| 490 | Diocese of Salerno was established |
| 490 | Diocese of Segni was established |
| 490 | Diocese of Sessa Aurunca was established |
| 490 | Diocese of Sorrento was established |
| 490 | Diocese of Taranto was established |
| 498 | Diocese of Tindari was established |
| 499 | Diocese of Cerveteri was established |
| 500 | Diocese of Agropoli was established |
| 500 | Diocese of Belluno was established |
| 500 | Diocese of Bevagna was established |
| 500 | Diocese of Bisenzio was established |
| 500 | Diocese of Blanda was established |
| 500 | Diocese of Bovino was established |
| 500 | Diocese of Bussento was established |
| 500 | Diocese of Cervia was established (became suffragan of Roma) |
| 500 | Diocese of Claterna was suppressed (to Diocese of Imola) |
| 500 | Diocese of Erdonia was suppressed (to Diocese of Eca) |
| 500 | Diocese of Falerone was suppressed |
| 500 | Diocese of Fausania was established (became suffragan of Cagliari) |
| 500 | Diocese of Fidene was established |
| 500 | Diocese of Foro Flaminii was established |
| 500 | Diocese of Gallipoli was established |
| 500 | Diocese of Isernia was established |
| 500 | Diocese of Labico was restored (from the suppressed Diocese of Subaugusta) |
| 500 | Diocese of Larino was established |
| 500 | Diocese of Lipari was established |
| 500 | Diocese of Locri was established |
| 500 | Diocese of Meria was established |
| 500 | Diocese of Messina was established |
| 500 | Diocese of Miseno was established |
| 500 | Diocese of Montecassino was suppressed (to Diocese of Aquino) |
| 500 | Diocese of Ostra was established |
| 500 | Diocese of Penne was established (without ecclesiastical province) |
| 500 | Diocese of Pollentia was suppressed (to Diocese of Camerino) |
| 500 | Diocese of Reggio Calabria was established |
| 500 | Diocese of Rieti was established (without ecclesiastical province) |
| 500 | Diocese of Senigallia was established (without ecclesiastical province) |
| 500 | Diocese of Sepino was established |
| 500 | Diocese of Spello was established |
| 500 | Diocese of Subaugusta was suppressed (to establish Diocese of Labico) |
| 500 | Diocese of Teramo was established (from the suppressed Diocese of Tronto) |
| 500 | Diocese of Treba was established |
| 500 | Diocese of Trevi was established |
| 500 | Diocese of Tronto was suppressed (to establish Diocese of Teramo) |
| 500 | Diocese of Venosa was established |
| 501.10.25 | Diocese of Lorium was suppressed (to establish Diocese of Santa Rufina) |
| 501.10.25 | Diocese of Santa Rufina was established (from the suppressed Diocese of Lorium) |
| 502 | Diocese of Aquaviva was suppressed (to Diocese of Santa Rufina) |
| 529 | Abbacy nullius of Montecassino was restored (from Diocese of Aquino) |
| 530 | Diocese of Bari was promoted as Metropolitan Archdiocese of Bari |
| 534 | Diocese of Bettona was suppressed (to Diocese of Assisi) |
| 542 | Diocese of Trieste was established (from Diocese of Cittanova and became suffragan of Aquileia) |
| 546 | Diocese of Strongoli was established |
| 550 | Diocese of Alatri was established (without ecclesiastical province) |
| 550 | Diocese of Anzio was suppressed (to Diocese of Albano) |
| 550 | Diocese of Arna was suppressed (to Diocese of Assisi) |
| 550 | Diocese of Carmeiano was suppressed |
| 550 | Diocese of Celano was suppressed |
| 550 | Diocese of Crotone was established |
| 550 | Diocese of Oderzo was established |
| 550 | Diocese of Ofena was suppressed (to Diocese of Valva) |
| 550 | Diocese of Ostra was suppressed (to Diocese of Senigallia) |
| 550 | Diocese of Potenza Picena was suppressed |
| 550 | Diocese of Sabiana was established (became suffragan of Aquileia) |
| 550 | Diocese of Terni was suppressed (to Diocese of Narni) |
| 557 | Diocese of Trieste lost territory to Diocese of Cittanova |
| 558 | Metropolitan Archdiocese of Aquileia was promoted as Patriarchal See of Aquileia |
| 560 | Diocese of Cingoli was suppressed (to Diocese of Osimo) |
| 560 | Diocese of Plestia was suppressed (to Diocese of Camerino) |
| 560 | Diocese of Septempeda was suppressed (to Diocese of Camerino) |
| 560 | Diocese of Tolentino was suppressed (to Diocese of Camerino) |
| 560 | Diocese of Treia was suppressed (to Diocese of Camerino) |
| 560 | Diocese of Urbisaglia was suppressed (to Diocese of Camerino) |
| 569 | Diocese of Altino lost territory to Diocese of Treviso |
| 569 | Diocese of Oderzo lost territory to Diocese of Treviso |
| 570 | Diocese of Feltre was established (became suffragan of Grado) |
| 570 | Patriarchal See of Grado was established (from Patriarchal See of Aquileia and with suffragan sees Belluno, Feltre, Malamocco and Padova) |
| 570 | Diocese of Malamocco was established (from Diocese of Padova and became suffragan of Grado) |
| 575 | Diocese of Egnazia Appula was suppressed (to Diocese of Brindisi) |
| 578 | Diocese of Matelica was suppressed (to Diocese of Camerino) |
| 580 | Diocese of Asolo was established |
| 580 | Abbacy nullius of Montecassino was suppressed |
| 580 | Diocese of Ortona was established |
| 580 | Diocese of Tarquinia was suppressed (to establish Diocese of Tuscanella) |
| 580 | Diocese of Tuscanella was established (from the suppressed Diocese of Tarquinia) |
| 580 | Diocese of Vicenza was established (from Diocese of Padova and became suffragan of Aquileia) |
| 590 | Diocese of Amalfi was established |
| 590 | Diocese of Nicotera was established |
| 590 | Diocese of Orvieto was established (from Diocese of Bolsena and without ecclesiastical province) |
| 590 | Diocese of Sant’Angelo in Vado was suppressed (to Diocese of Città di Castello and to establish Diocese of Urbino) |
| 590 | Diocese of Urbino was established (from the suppressed Diocese of Sant’Angelo in Vado) |
| 590 | Diocese of Uselli was established (became suffragan of Cagliari) |
| 592 | Diocese of Tre Taverne was suppressed (to Diocese of Velletri) |
| 593.02 | Diocese of Passo Corese was suppressed (to Diocese of Nomento) |
| 595.09 | Diocese of Carini was suppressed (to Diocese of Reggio Calabria) |
| 600 | Diocese of Agropoli was suppressed (to Diocese of Pesto) |
| 600 | Diocese of Alesa was established |
| 600 | Diocese of Aveia Vestina was suppressed (to establish Diocese of Forconio) |
| 600 | Diocese of Bagnoregio was established (from Diocese of Bolsena and without ecclesiastical province) |
| 600 | Diocese of Brixen was established (from the suppressed Diocese of Sabiana and became suffragan of Aquileia) |
| 600 | Diocese of Caorle was established (from Diocese of Concordia) |
| 600 | Diocese of Caudium was suppressed (to Diocese of Benevento) |
| 600 | Diocese of Cesena was established (became suffragan of Ravenna) |
| 600 | Diocese of Cirella was established |
| 600 | Diocese of Cosenza was established |
| 600 | Diocese of Forconio was established (from the suppressed Diocese of Aveia Vestina) |
| 600 | Diocese of Jesi was established (without ecclesiastical province) |
| 600 | Diocese of Malvito was established |
| 600 | Diocese of Milazzo was established |
| 600 | Diocese of Forum Clodii was renamed as Diocese of Monterano |
| 600 | Diocese of Roselle lost territory to Diocese of Siena |
| 600 | Diocese of Ruvo was established |
| 600 | Diocese of Sabiana was suppressed (to establish Diocese of Brixen) |
| 600 | Diocese of Tauriano was established |
| 602 | Diocese of Carini was restored (from Diocese of Reggio Calabria) |
| 610 | Diocese of Meria was renamed as Diocese of Tropea |
| 628.06.11 | Abbacy nullius of San Colombano was established (from Diocese of Piacenza) |
| 635 | Diocese of Eraclea was established (from the suppressed Diocese of Oderzo) |
| 635 | Diocese of Oderzo was suppressed (to establish Diocese of Eraclea) |
| 639 | Diocese of Altino was suppressed (to Diocese of Treviso and to establish Diocese of Torcello) |
| 639 | Diocese of Torcello was established (from the suppressed Diocese of Altino) |
| 640 | Diocese of Adria was established (became suffragan of Ravenna) |
| 653 | Diocese of Terni was restored (from Diocese of Narni) |
| 668 | Diocese of Eca lost territory to Diocese of Benevento |
| 670 | Diocese of Ceneda was established (from Diocese of Eraclea and became suffragan of Aquileia) |
| 670 | Diocese of Eraclea lost territory to Diocese of Treviso |
| 670 | Diocese of Sovana was established (became suffragan of Roma) |
| 670 | Diocese of Ventimiglia was established (became suffragan of Milano) |
| 674 | Diocese of Brindisi was renamed as Diocese of Brindisi–Oria |
| 680 | Diocese of Bisenzio was suppressed (to establish Diocese of Castro del Lazio) |
| 680 | Diocese of Brescello was suppressed (to establish Diocese of Parma) |
| 680 | Diocese of Castro del Lazio was established (from the suppressed Diocese of Bisenzio) |
| 680 | Diocese of Cefalù was established (became suffragan of Siracusa) |
| 680 | Diocese of Parma was restored (from the suppressed Diocese of Brescello and became suffragan of Milano) |
| 680 | Diocese of Siracusa was promoted as Metropolitan Archdiocese of Siracusa (with suffragan sees Cefalù and Messina) |
| 680 | Diocese of Vado Ligure was established (became suffragan of Milano) |
| 682 | Diocese of Castro was established |
| 690 | Diocese of Bolsena was suppressed (to Diocese of Orvieto) |
| 700 | Diocese of Alessano was established |
| 700 | Diocese of Bisarcio was established |
| 700 | Diocese of Bussento was suppressed |
| 700 | Diocese of Pitinum Merges was renamed as Diocese of Cagli |
| 700 | Diocese of Comacchio was established (became suffragan of Ravenna) |
| 700 | Diocese of Ferento was suppressed (to Diocese of Bomarzo) |
| 700 | Diocese of Fidene was suppressed |
| 700 | Diocese of Gallese was established |
| 700 | Diocese of Grumentum was suppressed |
| 700 | Diocese of Miseno was suppressed (to Diocese of Cuma) |
| 700 | Diocese of Orte was established |
| 700 | Diocese of Ortona was suppressed (to Diocese of Chieti) |
| 700 | Diocese of Otricoli was suppressed (to Diocese of Narni) |
| 700 | Diocese of Polignano was established |
| 700 | Abbacy nullius of Pomposa was established |
| 700 | Diocese of Rosella was established |
| 700 | Diocese of Tharros was renamed as Diocese of Sinis-Tharros |
| 700 | Diocese of Sulci was suppressed |
| 700 | Diocese of Trento lost territory to Diocese of Feltre and Diocese of Sabiana |
| 718 | Abbacy nullius of Montecassino was restored |
| 730 | Diocese of Reggio Calabria was promoted as Metropolitan Archdiocese of Reggio Calabria (with suffragan sees Cosenza, Locri, Nicotera, Tauriano, Tropea and Vibo Valentia) |
| 740 | Diocese of Bisignano was established (from Diocese of Thurio and became suffragan of Reggio Calabria) |
| 740 | Diocese of Conza was established |
| 740 | Diocese of Veroli was established (without ecclesiastical province) |
| 740 | Diocese of Zuglio was suppressed (to Patriarchal See of Aquileia) |
| 743 | Diocese of Torres was suppressed |
| 744 | Diocese of Aquino lost territory to Abbacy nullius of Montecassino |
| 744 | Diocese of Formia lost territory to Abbacy nullius of Montecassino |
| 744 | Diocese of Teano lost territory to Abbacy nullius of Montecassino |
| 744 | Diocese of Venafro lost territory to Abbacy nullius of Montecassino |
| 750 | Diocese of Fausania was suppressed |
| 750 | Abbacy nullius of Nonantola was established (from Diocese of Modena) |
| 750 | Diocese of Sala Consilina was suppressed (to Diocese of Pesto) |
| 750 | Diocese of Suèssola was established |
| 750 | Diocese of Tre Taverne was restored (from Diocese of Velletri) |
| 760 | Diocese of Priverno was established (without ecclesiastical province) |
| 760 | Diocese of Terni was suppressed (to Diocese of Spoleto) |
| 774 | Diocese of Olivolo was established (from Diocese of Malamocco and became suffragan of Grado) |
| 775 | Abbacy nullius of Farfa was established |
| 785 | Diocese of Montefeltro was established (became suffragan of Ravenna) |
| 787 | Diocese of Locri was renamed as Diocese of Santa Ciriaca |
| 790 | Diocese of Sezze was established (without ecclesiastical province) |
| 800 | Diocese of Cornus was suppressed (to Diocese of Sinis-Tharros) |
| 800 | Diocese of Equilio was established |
| 800 | Diocese of Foro Flaminii was suppressed (to Diocese of Foligno) |
| 800 | Diocese of Genova lost territory to Diocese of Tortona |
| 800 | Diocese of Gravina was established |
| 800 | Diocese of Norma was established |
| 800 | Diocese of Pavia lost territory to Diocese of Tortona |
| 800 | Diocese of Venafro was suppressed |
| 804 | Diocese of Mantova was established (from Diocese of Verona and became suffragan of Aquileia) |
| 820 | Diocese of Massa Marittima e Populonia was established (from the suppressed Diocese of Populonia) |
| 820 | Diocese of Populonia was suppressed (to establish Diocese of Massa Marittima e Populonia) |
| 827 | Diocese of Carini was suppressed |
| 835 | Diocese of Agrigento was suppressed |
| 837 | Diocese of Tricala was suppressed |
| 844 | Diocese of Canosa lost territory to Diocese of Trani |
| 844 | Diocese of Sepino was suppressed |
| 846 | Diocese of Formia was suppressed (to establish Diocese of Gaeta) |
| 846 | Diocese of Gaeta was established (from the suppressed Diocese of Formia and without ecclesiastical province) |
| 870 | Diocese of Cefalù was suppressed |
| 870 | Diocese of Otranto was promoted as Archdiocese of Otranto |
| 870 | Diocese of Tre Taverne was suppressed (to Diocese of Velletri) |
| 878 | Diocese of Alesa was suppressed |
| 878 | Diocese of Lipari was suppressed |
| 878.05.21 | Metropolitan Archdiocese of Siracusa was suppressed |
| 880 | Diocese of Catania was suppressed |
| 880 | Diocese of Lentini was suppressed |
| 880 | Diocese of Messina was suppressed |
| 880 | Diocese of Tindari was suppressed |
| 885 | Metropolitan Archdiocese of Santa Severina was established (from Diocese of Crotone and with suffragan see Gallipoli) |
| 890 | Diocese of Gabi was suppressed (to Diocese of Palestrina) |
| 890 | Diocese of Termini Imerese was suppressed |
| 893 | Diocese of Bovino was suppressed (to Diocese of Benevento) |
| 900 | Diocese of Amantea was established (became suffragan of Reggio Calabria) |
| 900 | Diocese of Bevagna was suppressed (to Diocese of Spoleto) |
| 900 | Diocese of Canne was established |
| 900 | Diocese of Eraclea was suppressed (to Diocese of Belluno) |
| 900 | Diocese of Santa Ciriaca was renamed as Diocese of Locri |
| 900 | Diocese of Marsi was established |
| 900 | Diocese of Matera was established (from Diocese of Acerenza) |
| 900 | Diocese of Milazzo was suppressed |
| 900 | Diocese of Minervino was established |
| 900 | Diocese of Monterano was suppressed (to Diocese of Sutri) |
| 900 | Diocese of Nicastro was established (became suffragan of Reggio Calabria) |
| 900 | Diocese of Orvieto lost territory to Diocese of Bagnoregio |
| 900 | Diocese of Perugia lost territory to Diocese of Bagnoregio |
| 900 | Abbacy nullius of San Colombano lost territory to Diocese of Tortona |
| 900 | Diocese of Spello was suppressed (to Diocese of Spoleto) |
| 902 | Diocese of Nicotera was suppressed (to Diocese of Tropea) |
| 906 | Diocese of Taormina was suppressed |
| 910 | Diocese of Lilibeo was suppressed |
| 917 | Diocese of Vicenza lost territory to Diocese of Padova |
| 940 | Diocese of Termoli was established |
| 940 | Diocese of Trivento was established |
| 944.05 | Diocese of Nomento was suppressed (to Diocese of Vescovìo) |
| 950 | Diocese of Belcastro was established (from Metropolitan Archdiocese of Santa Severina and became suffragan of Santa Severina) |
| 950 | Diocese of Blanda was suppressed (to establish Diocese of Cassano all’Jonio) |
| 950 | Diocese of Cassano all’Jonio was established (from the suppressed Diocese of Blanda and Diocese of Thurio) |
| 950 | Diocese of Ferrara was established (from the suppressed Diocese of Voghenza and became suffragan of Milano) |
| 950 | Diocese of Plestia was restored (from Diocese of Camerino) |
| 950 | Diocese of Rossano was established (from the suppressed Diocese of Thurio and became suffragan of Reggio Calabria) |
| 950 | Diocese of Thurio was suppressed (to establish Diocese of Cassano all’Jonio and Diocese of Rossano) |
| 950 | Diocese of Voghenza was suppressed (to establish Diocese of Ferrara) |
| 956 | Archdiocese of Otranto was promoted as Metropolitan Archdiocese of Otranto (with suffragan sees Acerenza and Alessano) |
| 960 | Diocese of Ariano was established |
| 960 | Diocese of Atina was established (from Diocese of Sora) |
| 960 | Diocese of Cerenzia was established |
| 966.08.14 | Diocese of Caiazzo was established (became suffragan of Capua) |
| 966.08.14 | Diocese of Capua was promoted as Metropolitan Archdiocese of Capua (with suffragan sees Aquino, Atina, Caiazzo, Calvi, Fondi, Forum claudii, Gaeta, Sessa Aurunca, Sora and Teano) |
| 968 | Diocese of Tricarico was established (became suffragan of Otranto) |
| 968 | Diocese of Tursi was established |
| 969.05.26 | Diocese of Ascoli Satriano was established (from Diocese of Benevento and became suffragan of Benevento) |
| 969.05.26 | Diocese of Benevento was promoted as Metropolitan Archdiocese of Benevento (with suffragan sees Alife, Ariano, Ascoli Satriano, Avellino, Eclena, Larino, Sant’Agata de’ Goti, Siponto and Telese and lost territory to establish Diocese of Ascoli Satriano and Diocese of Sant’Agata de’ Goti) |
| 969.05.26 | Diocese of Sant’Agata de’ Goti was established (from Diocese of Benevento and became suffragan of Benevento) |
| 969.08.10 | Diocese of Asolo was suppressed (to Diocese of Padova, Diocese of Treviso and Diocese of Vicenza) |
| 970 | Diocese of Bovino was restored (from Metropolitan Archdiocese of Benevento and became suffragan of Benevento) |
| 970 | Diocese of Norma was suppressed (to Diocese of Velletri) |
| 970 | Diocese of Taranto was promoted as Metropolitan Archdiocese of Taranto |
| 983.06 | Diocese of Salerno was promoted as Metropolitan Archdiocese of Salerno (with suffragan sees Acerenza, Bisignano, Conza, Cosenza, Malvito, Nola and Pesto) |
| 984 | Diocese of Lavello was established |
| 987.02.13 | Diocese of Amalfi was promoted as Metropolitan Archdiocese of Amalfi (with suffragan sees Capri, Lettere, Minori and Scala and lost territory to establish Diocese of Capri, Diocese of Lettere, Diocese of Minori and Diocese of Scala) |
| 987.02.13 | Diocese of Capri was established (from Diocese of Amalfi and became suffragan of Amalfi) |
| 987.02.13 | Diocese of Lettere was established (from Diocese of Amalfi and became suffragan of Amalfi) |
| 987.02.13 | Diocese of Minori was established (from Diocese of Amalfi and became suffragan of Amalfi) |
| 987.02.13 | Diocese of Scala was established (from Diocese of Amalfi and became suffragan of Amalfi) |
| 990 | Diocese of Vieste was established (from Diocese of Siponto) |
| 992 | Diocese of Vado Ligure was renamed as Diocese of Savona |
| 996 | Diocese of Eraclea was restored (from Diocese of Belluno) |
| 999.01.07 | Diocese of Treviso lost territory to Diocese of Eraclea |
| 1000 | Diocese of Acquaputrida was established (became suffragan of Benevento) |
| 1000 | Diocese of Biccari was established (became suffragan of Benevento) |
| 1000 | Diocese of Bitonto was established (became suffragan of Bari) |
| 1000 | Diocese of Città della Pieve was established (without ecclesiastical province) |
| 1000 | Diocese of Gravina was suppressed |
| 1000 | Diocese of Minturno was suppressed (to Diocese of Gaeta) |
| 1000 | Diocese of Montepeloso was established |
| 1000 | Diocese of Napoli was promoted as Metropolitan Archdiocese of Napoli (with suffragan see Pozzuoli) |
| 1000 | Diocese of Norcia was suppressed (to Diocese of Spoleto) |
| 1000 | Diocese of Rossano was promoted as Archdiocese of Rossano |
| 1000 | Abbacy nullius of Sacra di San Michele was established |
| 1000 | Abbacy nullius of San Pietro di Novalesa was established (from Diocese of Torino) |
| 1000 | Abbacy nullius of Santa Maria di Sesto was established |
| 1000 | Abbacy nullius of Santa Maria di Vangadizza was established |
| 1000 | Diocese of Sarno was established (became suffragan of Salerno) |
| 1000 | Diocese of Sinis-Tharros was promoted as Metropolitan Archdiocese of Sinis-Tharros |
| 1000 | Diocese of Tocco Caudio was established (became suffragan of Benevento) |
| 1000 | Diocese of Trevico was established (became suffragan of Benevento) |
| 1002 | Diocese of Suelli was established |
| 1006 | Diocese of Gualdo Tadino was suppressed (to Diocese of Nocera Umbra) |
| 1006 | Diocese of Plestia was suppressed (to Diocese of Foligno, Diocese of Nocera Umbra and Diocese of Spoleto) |
| 1013 | Abbacy nullius of Sansepolcro was established (from Diocese of Città di Castello) |
| 1014.02.14 | Diocese of Bobbio was established (from Diocese of Piacenza, Diocese of Tortona and Abbacy nullius of San Colombano) |
| 1015 | Diocese of Bomarzo was suppressed (to Diocese of Bagnoregio) |
| 1015 | Diocese of Tortiboli was established (became suffragan of Benevento) |
| 1019 | Diocese of Eca was suppressed (to establish Diocese of Troia) |
| 1019 | Diocese of Troia was established (from the suppressed Diocese of Eca) |
| 1020 | Diocese of Giovinazzo was established (became suffragan of Bari) |
| 1020 | Diocese of Molfetta was established (became suffragan of Bari) |
| 1023 | Diocese of Castellaneta was established (became suffragan of Taranto) |
| 1023 | Diocese of Mottola was established (became suffragan of Taranto) |
| 1025 | Diocese of Oppido Mamertina was established (from Diocese of Tauriano and became suffragan of Reggio Calabria) |
| 1030 | Diocese of Brindisi–Oria was promoted as Metropolitan Archdiocese of Brindisi–Oria (with suffragan see Monopoli and lost territory to establish Diocese of Monopoli) |
| 1030 | Diocese of Monopoli was established (from Diocese of Brindisi–Oria and became suffragan of Brindisi–Oria) |
| 1030 | Diocese of Umbriatico was established |
| 1032 | Diocese of Venafro was restored (became suffragan of Capua) |
| 1033 | Diocese of Civita Castellana was established (from the suppressed Diocese of Faleri and without ecclesiastical province) |
| 1033 | Diocese of Faleri was suppressed (to establish Diocese of Civita Castellana) |
| 1036 | Diocese of Ischia was established (became suffragan of Napoli) |
| 1039 | Diocese of Dragonara was established (became suffragan of Benevento) |
| 1040 | Diocese of Luni lost territory to Diocese of Massa Marittima e Populonia |
| 1040 | Diocese of Muro Lucano was established |
| 1042 | Diocese of Montepeloso was suppressed (to Diocese of Tricarico) |
| 1047 | Abbacy nullius of San Giovanni in Venere was established (from Diocese of Chieti) |
| 1049 | Diocese of Monteverde was established (became suffragan of Salerno) |
| 1050 | Diocese of Cefalù lost territory to Diocese of Palermo |
| 1050 | Diocese of Cerveteri was suppressed (to Diocese of Porto) |
| 1050 | Diocese of Massa Lubrense was established (from Diocese of Sorrento) |
| 1050 | Diocese of Melfi was established (without ecclesiastical province) |
| 1050 | Diocese of Montemarano was established (became suffragan of Benevento) |
| 1050 | Diocese of Ostuni was established (from Metropolitan Archdiocese of Brindisi–Oria and became suffragan of Brindisi–Oria) |
| 1050 | Diocese of Sorrento was promoted as Metropolitan Archdiocese of Sorrento (with suffragan see Castellammare di Stabia and lost territory to establish Diocese of Massa Lubrense and Diocese of Vico Equense) |
| 1050 | Diocese of Sulci was restored |
| 1050 | Diocese of Vico Equense was established (from Diocese of Sorrento) |
| 1053 | Diocese of Atella was suppressed (to establish Diocese of Aversa) |
| 1053 | Diocese of Aversa was established (from the suppressed Diocese of Atella and Diocese of Liternium and became suffragan of Napoli) |
| 1053 | Diocese of Liternium was suppressed (to establish Diocese of Aversa) |
| 1054 | Diocese of Luni lost territory to Diocese of Pisa |
| 1056 | Diocese of Acerra was established (from the suppressed Diocese of Suèssola and became suffragan of Napoli) |
| 1056 | Diocese of Suèssola was suppressed (to Diocese of Sant’Agata de’ Goti and to establish Diocese of Acerra) |
| 1057 | Diocese of Lecce was established (became suffragan of Otranto) |
| 1057 | Diocese of Senigallia lost territory to Diocese of Fossombrone |
| 1058.03.24 | Diocese of Marsico Nuovo was established (from former Diocese of Grumentum and became suffragan of Salerno) |
| 1058.03.24 | Diocese of Martirano was established (became suffragan of Salerno) |
| 1058.03.24 | Diocese of Policastro was established (from former Diocese of Bussento and became suffragan of Salerno) |
| 1059 | Diocese of Acerenza was promoted as Archdiocese of Acerenza |
| 1059 | Diocese of Eclena was suppressed (to establish Diocese of Frigento) |
| 1059 | Diocese of Fiorentino was established (became suffragan of Benevento) |
| 1059 | Diocese of Frigento was established (from the suppressed Diocese of Eclena and became suffragan of Benevento) |
| 1059 | Diocese of Guardialfiera was established (became suffragan of Benevento) |
| 1059 | Diocese of Montecorvino was established (became suffragan of Benevento) |
| 1059 | Diocese of Nicotera was restored (from Diocese of Tropea) |
| 1059 | Diocese of Vulturara was established (became suffragan of Benevento) |
| 1059.05 | Diocese of Cosenza was promoted as Archdiocese of Cosenza |
| 1060 | Diocese of Amiterno was suppressed (to Diocese of Rieti) |
| 1060 | Diocese of Boiano was established (became suffragan of Benevento) |
| 1060 | Diocese of Civitate was established |
| 1060 | Diocese of Gravina was restored |
| 1060 | Diocese of Rapolla was established (without ecclesiastical province) |
| 1063 | Diocese of Trani was promoted as Metropolitan Archdiocese of Trani |
| 1064 | Diocese of Siponto was promoted as Archdiocese of Siponto |
| 1065 | Diocese of Carini lost territory to Metropolitan Archdiocese of Palermo |
| 1065 | Diocese of Lilibeo lost territory to Metropolitan Archdiocese of Palermo |
| 1065 | Diocese of Palermo was promoted as Metropolitan Archdiocese of Palermo (gained territory from Diocese of Carini, Diocese of Lilibeo and Diocese of Termini Imerese) |
| 1065 | Diocese of Termini Imerese lost territory to Metropolitan Archdiocese of Palermo |
| 1068.04.13 | Archdiocese of Acerenza was promoted as Metropolitan Archdiocese of Acerenza (with suffragan sees Gravina, Matera, Potenza, Tricarico, Tursi and Venosa) |
| 1070 | Diocese of Bisceglie was established |
| 1070 | Diocese of Bova was established (from Diocese of Locri) |
| 1070 | Diocese of Dolia was established |
| 1070 | Diocese of Gallura was restored |
| 1073 | Diocese of Ampurias was established (became suffragan of Torres) |
| 1073 | Diocese of Bosa was established (from Metropolitan Archdiocese of Sinis-Tharros and became suffragan of Torres) |
| 1073 | Diocese of Castro was established (became suffragan of Torres) |
| 1073 | Diocese of Sorres was established (became suffragan of Torres) |
| 1073 | Metropolitan Archdiocese of Torres was restored (with suffragan sees Ampurias, Bisarcio, Bosa, Castro and Sorres) |
| 1074 | Diocese of Olivolo was renamed as Diocese of Castello |
| 1076 | Diocese of Nusco was established (from Metropolitan Archdiocese of Benevento and became suffragan of Salerno) |
| 1078 | Abbacy nullius of San Michele Arcangelo di Montescaglioso was established |
| 1078 | Abbacy nullius of Santa Maria ad Abbadia Alpina was established |
| 1080 | Diocese of Conversano was established (from Metropolitan Archdiocese of Bari and became suffragan of Bari) |
| 1080 | Diocese of Conza was promoted as Metropolitan Archdiocese of Conza (with suffragan sees Lacedonia, Monteverde, Muro Lucano and Sant’Angelo dei Lombardi) |
| 1080 | Diocese of Forum Traiani was suppressed (to establish Diocese of Santa Giusta) |
| 1080 | Diocese of Locri was renamed as Diocese of Gerace |
| 1080 | Diocese of Lacedonia was established (became suffragan of Conza) |
| 1080 | Diocese of Santa Giusta was established (from the suppressed Diocese of Forum Traiani) |
| 1080 | Diocese of Sant’Angelo dei Lombardi was established (became suffragan of Conza) |
| 1080 | Diocese of Ugento was established |
| 1081 | Metropolitan Archdiocese of Reggio Calabria lost territory to Diocese of Bova and Diocese of Oppido Mamertina |
| 1081 | Abbacy nullius of Santissimo Salvatore (Italo-Albanese Rite) was established |
| 1081.02.04 | Diocese of Mileto was established (from the suppressed Diocese of Vibo Valentia and without ecclesiastical province) |
| 1081.02.04 | Diocese of Vibo Valentia was suppressed (to establish Diocese of Mileto) |
| 1082 | Diocese of Matera was suppressed (to Metropolitan Archdiocese of Acerenza) |
| 1082 | Diocese of Troina was established (from former Diocese of Lipari, former Diocese of Messina, former Diocese of Taormina and former Diocese of Tindari) |
| 1086 | Diocese of Ravello was established (from Metropolitan Archdiocese of Amalfi and without ecclesiastical province) |
| 1086 | Diocese of Siracusa was restored (from former Diocese of Catania and former Diocese of Lentini) |
| 1088 | Diocese of Agrigento was restored (from Metropolitan Archdiocese of Palermo and former Diocese of Tricala and without ecclesiastical province) |
| 1088.08.23 | Diocese of Treba was suppressed (to Diocese of Anagni) |
| 1090 | Diocese of Acerno was established (became suffragan of Salerno) |
| 1090 | Diocese of Bisaccia was established (became suffragan of Conza) |
| 1090 | Abbacy nullius of Nardò was established (from Diocese of Gallipoli) |
| 1090 | Diocese of Ploaghe was established (became suffragan of Torres) |
| 1092.03.09 | Diocese of Catania was restored (from Diocese of Siracusa) |
| 1092.04.21 | Diocese of Pisa was promoted as Metropolitan Archdiocese of Pisa (with suffragan sees Accia, Mariana and Nebbio) |
| 1093 | Diocese of Blera was suppressed (to Diocese of Tuscanella) |
| 1093 | Diocese of Civitavecchia was suppressed (to Diocese of Tuscanella) |
| 1093 | Diocese of Mazara del Vallo was established (from Metropolitan Archdiocese of Palermo and became suffragan of Palermo) |
| 1093 | Metropolitan Archdiocese of Oristano was established (from the suppressed Metropolitan Archdiocese of Sinis-Tharros and with suffragan see Uselli) |
| 1093 | Metropolitan Archdiocese of Sinis-Tharros was suppressed (to establish Metropolitan Archdiocese of Oristano) |
| 1093.10.03 | Diocese of Tauriano was suppressed (to Diocese of Mileto) |
| 1094 | Diocese of Amantea was suppressed (to Diocese of Tropea) |
| 1098 | Diocese of Messina was restored (from the suppressed Diocese of Troina) |
| 1098 | Abbacy nullius of Santissima Trinità di Mileto was established |
| 1098 | Diocese of Troina was suppressed (to establish Diocese of Messina) |
| 1098.07.20 | Diocese of Satriano was established (became suffragan of Conza) |
| 1099 | Diocese of Forum claudii was renamed as Diocese of Carinola |
| 1099 | Diocese of Città della Pieve was suppressed (to Diocese of Chiusi) |
| 1099 | Archdiocese of Siponto was promoted as Metropolitan Archdiocese of Siponto (with suffragan see Vieste) |
| 1100 | Diocese of Acquaputrida was suppressed (to Diocese of Frigento) |
| 1100 | Diocese of Andria was established (from Metropolitan Archdiocese of Trani and became suffragan of Trani) |
| 1100 | Diocese of Biccari was suppressed |
| 1100 | Diocese of Limosano was established (became suffragan of Benevento) |
| 1100 | Abbacy nullius of Massa Carrara was established (from Diocese of Lucca) |
| 1100 | Diocese of Rosella was suppressed |
| 1100 | Territorial Abbacy of Subiaco was established (from Diocese of Tivoli) |
| 1100 | Diocese of Tocco Caudio was suppressed |
| 1100 | Metropolitan Archdiocese of Trani lost territory to Metropolitan Archdiocese of Nazareth |
| 1100 | Diocese of Trevi was suppressed (to Diocese of Spoleto) |
| 1101.08.07 | Metropolitan Archdiocese of Bari was renamed as Metropolitan Archdiocese of Bari e Canosa |
| 1101.08.07 | Diocese of Canosa was demoted as Archpresbyterate nullius of Canosa |
| 1106 | Diocese of Chioggia was established (from the suppressed Diocese of Malamocco and became suffragan of Grado) |
| 1106 | Diocese of Malamocco was suppressed (to establish Diocese of Chioggia) |
| 1110 | Diocese of Anglona was established (from the suppressed Diocese of Tursi and became suffragan of Acerenza) |
| 1110 | Diocese of Ottana was established (became suffragan of Torres) |
| 1110 | Archpresbyterate nullius of Santa Maria Assunta di Carpi was established (from Diocese of Reggio Emilia) |
| 1110 | Diocese of Tursi was suppressed (to establish Diocese of Anglona) |
| 1113 | Diocese of Caserta was established (from Metropolitan Archdiocese of Capua, from the suppressed Diocese of Galazia in Campania and became suffragan of Napoli) |
| 1113 | Diocese of Gallura was renamed as Diocese of Civita |
| 1113 | Diocese of Galazia in Campania was suppressed (to establish Diocese of Caserta) |
| 1114 | Provostry nullius of Borgo San Donnino was established (from Diocese of Parma and Diocese of Piacenza) |
| 1114 | Diocese of Isola was established |
| 1119 | Diocese of Porto was renamed as Diocese of Porto e Santa Rufina (gained territory from the suppressed Diocese of Santa Rufina) |
| 1119 | Diocese of Santa Rufina was suppressed (to Diocese of Porto e Santa Rufina) |
| 1120 | Diocese of Galtellì was established (from Diocese of Civita) |
| 1120 | Diocese of Labico was suppressed (to establish Diocese of Tusculum) |
| 1120 | Diocese of Tusculum was established (from the suppressed Diocese of Labico and became suffragan of Roma) |
| 1121 | Diocese of Catanzaro was established (from Diocese of Squillace) |
| 1123 | Diocese of Montepeloso was restored (from Diocese of Tricarico and became suffragan of Acerenza) |
| 1126.05 | Territorial Abbacy of Montevergine was established (from Diocese of Avellino and became suffragan of Benevento) |
| 1130 | Diocese of Terralba was established |
| 1131.09.04 | Diocese of Cefalù was restored (from Diocese of Agrigento) |
| 1133 | Diocese of Montepeloso was suppressed (to Diocese of Andria) |
| 1133.03.19 | Diocese of Genova was promoted as Metropolitan Archdiocese of Genova (with suffragan sees Accia, Bobbio, Mariana and Nebbio) |
| 1133.05.27 | Diocese of Brugnato was established (from Metropolitan Archdiocese of Genova and Diocese of Luni and became suffragan of Genova) |
| 1138.04.09 | Diocese of Grosseto was established (from the suppressed Diocese of Roselle and became suffragan of Roma) |
| 1138.04.09 | Diocese of Roselle was suppressed (to establish Diocese of Grosseto) |
| 1140 | Diocese of Atina was demoted as Provostry nullius of Atina (lost territory to Diocese of Sora and without ecclesiastical province) |
| 1140 | Abbacy nullius of Santi Vincenzo ed Anastasio alle Tre Fontane was established |
| 1144 | Abbacy nullius of Fontevivo was established (from Diocese of Parma) |
| 1144 | Abbacy nullius of Santa Maria di Polsi was established |
| 1150 | Diocese of Ostia was renamed as Diocese of Ostia–Velletri (gained territory from the suppressed Diocese of Velletri) |
| 1150 | Diocese of Velletri was suppressed (to Diocese of Ostia–Velletri) |
| 1153 | Diocese of Limosano was suppressed (to Metropolitan Archdiocese of Benevento) |
| 1157 | Diocese of Lipari was restored (from Diocese of Messina) |
| 1157 | Diocese of Patti was established (from Diocese of Messina) |
| 1159 | Diocese of Cirella was suppressed (to establish Diocese of San Marco) |
| 1159 | Diocese of Malvito was suppressed (to establish Diocese of San Marco) |
| 1159 | Diocese of San Marco was established (from the suppressed Diocese of Cirella and Diocese of Malvito and without ecclesiastical province) |
| 1160 | Diocese of Capaccio was established (from the suppressed Diocese of Pesto and became suffragan of Salerno) |
| 1160 | Diocese of Pesto was suppressed (to establish Diocese of Capaccio) |
| 1162 | Diocese of Albenga lost territory to Metropolitan Archdiocese of Genova |
| 1162 | Diocese of Luni lost territory to Metropolitan Archdiocese of Genova |
| 1166 | Diocese of Messina was promoted as Metropolitan Archdiocese of Messina (with suffragan sees Cefalù, Lipari and Patti) |
| 1169 | Diocese of Lettere was renamed as Diocese of Lettere–Gragnano |
| 1170 | Diocese of Bitetto was established (from Metropolitan Archdiocese of Bari e Canosa) |
| 1174 | Abbacy nullius of Santa Maria Nuova di Monreale was established (from Metropolitan Archdiocese of Palermo) |
| 1175 | Diocese of Alessandria was established (from Diocese of Acqui, Diocese of Asti and Diocese of Tortona and became suffragan of Milano) |
| 1176 | Diocese of Mazara del Vallo lost territory to Abbacy nullius of Santa Maria Nuova di Monreale |
| 1176 | Metropolitan Archdiocese of Palermo lost territory to Abbacy nullius of Santa Maria Nuova di Monreale |
| 1177 | Diocese of Treviso lost territory to Diocese of Torcello |
| 1179 | Archdiocese of Cosenza was promoted as Metropolitan Archdiocese of Cosenza (with suffragan see Martirano) |
| 1182 | Diocese of Uselli was renamed as Diocese of Ales |
| 1183.02.05 | Abbacy nullius of Santa Maria Nuova di Monreale was promoted as Metropolitan Archdiocese of Monreale (with suffragan see Catania) |
| 1191 | Abbacy nullius of San Salvatore Maggiore was established (from Diocese of Rieti) |
| 1191 | Diocese of Tusculum was renamed as Diocese of Tusculum–Frascati |
| 1192.08.03 | Diocese of Viterbo was established (from Diocese of Tuscanella and without ecclesiastical province) |
| 1194 | Diocese of Sovana lost territory to Diocese of Orvieto |
| 1198 | Diocese of Assisi lost territory to Diocese of Perugia |
| 1198 | Diocese of Imola lost territory to Diocese of Bologna |
| 1200 | Diocese of Lesina was established (became suffragan of Benevento) |
| 1200 | Abbacy nullius of San Giusto di Susa was established (from Diocese of Torino) |
| 1200 | Diocese of San Leone was established (from Diocese of Belcastro) |
| 1203.05.07 | Archdiocese of Matera was restored (from Metropolitan Archdiocese of Acerenza) |
| 1206 | Territorial Prelature of Santa Lucia del Mela was established (from Diocese of Patti and without ecclesiastical province) |
| 1207 | Diocese of Cuma was suppressed (to Diocese of Aversa and Diocese of Pozzuoli) |
| 1218.01.13 | Diocese of Terni was restored (from Diocese of Narni and Diocese of Spoleto and without ecclesiastical province) |
| 1221.03.26 | Archpresbyterate nullius of Acquaviva delle Fonti was established (from Metropolitan Archdiocese of Bari e Canosa) |
| 1228 | Diocese of Fiesole exchanged territory with Diocese of Firenze |
| 1228 | Diocese of Firenze exchanged territory with Diocese of Fiesole |
| 1230 | Metropolitan Archdiocese of Siponto was renamed as Metropolitan Archdiocese of Manfredonia |
| 1230 | Diocese of Sovana lost territory to Abbacy nullius of Santi Vincenzo ed Anastasio alle Tre Fontane |
| 1239 | Diocese of Noli was established (from Diocese of Savona and became suffragan of Genova) |
| 1240 | Diocese of Comacchio lost territory to Diocese of Cervia |
| 1240.05.22 | Diocese of Osimo was suppressed (to establish Diocese of Recanati) |
| 1240.05.22 | Diocese of Recanati was established (from Diocese of Numana and from the suppressed Diocese of Osimo) |
| 1240.11.15 | Diocese of Recanati lost territory to Diocese of Numana |
| 1243 | Diocese of Lodi was suppressed |
| 1248 | Archpresbyterate nullius of Altamura was established (from Diocese of Bitetto) |
| 1248 | Diocese of Tortona lost territory to Metropolitan Archdiocese of Genova |
| 1251.04.01 | Diocese of Atri was established (from Diocese of Penne) |
| 1252 | Diocese of Lodi was restored (became suffragan of Milano) |
| 1257.02.20 | Diocese of Forconio was suppressed (to establish Diocese of L’Aquila) |
| 1257.02.20 | Diocese of L’Aquila was established (from Diocese of Rieti and from the suppressed Diocese of Forconio) |
| 1260 | Diocese of Nuceria was suppressed (to Metropolitan Archdiocese of Amalfi and Metropolitan Archdiocese of Salerno) |
| 1263.07.27 | Diocese of Recanati was suppressed (to Diocese of Numana) |
| 1264.03.13 | Diocese of Osimo was restored (from Diocese of Numana) |
| 1285 | Diocese of Gallese was suppressed (to Diocese of Civita Castellana) |
| 1289.12.01 | Diocese of Recanati was restored (from Diocese of Numana) |
| 1300 | Abbacy nullius of San Martino al Monte Cimino was established |
| 1304 | Diocese of Nicotera was suppressed (to Diocese of Mileto) |
| 1310 | Diocese of Mileto lost territory to Metropolitan Archdiocese of Reggio Calabria |
| 1320 | Diocese of Osimo was renamed as Diocese of Osimo e Cingoli |
| 1320.11.18 | Diocese of Macerata was established (from Diocese of Camerino and Diocese of Fermo and from the suppressed Diocese of Recanati) |
| 1320.11.18 | Diocese of Recanati was suppressed (to establish Diocese of Macerata) |
| 1322.05.02 | Abbacy nullius of Montecassino was promoted as Diocese of Montecassino |
| 1325.06.19 | Diocese of Cortona was established (from Diocese of Arezzo, Diocese of Chiusi and Diocese of Città di Castello) |
| 1327 | Metropolitan Archdiocese of Nazareth in Barletta was established (from Metropolitan Archdiocese of Trani and from the suppressed Metropolitan Archdiocese of Nazareth) |
| 1334 | Diocese of Eraclea lost territory to Diocese of Treviso |
| 1356.01.08 | Diocese of Recanati was restored (from Diocese of Macerata) |
| 1360 | Diocese of Bertinoro was established (from the suppressed Diocese of Forlimpopoli) |
| 1360 | Diocese of Forlimpopoli was suppressed (to establish Diocese of Bertinoro) |
| 1367.03.31 | Diocese of Montecassino was demoted as Territorial Abbacy of Montecassino |
| 1368.07.12 | Diocese of Osimo e Cingoli was renamed as Diocese of Osimo |
| 1369.08.31 | Diocese of Montefiascone was established (from Diocese of Bagnoregio, Diocese of Castro del Lazio, Diocese of Orvieto, Diocese of Tuscanella and Diocese of Viterbo) |
| 1384.10.10 | Diocese of Nuceria was restored (from Metropolitan Archdiocese of Amalfi and Metropolitan Archdiocese of Salerno and became suffragan of Salerno) |
| 1386 | Collegiate nullius of Colle di Val d’Elsa was established (from Diocese of Volterra) |
| 1388.06.05 | Diocese of Mondovì was established (from Diocese of Asti and became suffragan of Milano) |
| 1392.08.14 | Diocese of Nicotera was restored (from Metropolitan Archdiocese of Reggio Calabria and became suffragan of Reggio Calabria) |
| 1394.08.07 | Diocese of Cava was established (from Metropolitan Archdiocese of Salerno and without ecclesiastical province) |
| 1401.03.08 | Abbacy nullius of San Cristoforo di Castel Durante was established (from Diocese of Urbino) |
| 1410 | Diocese of Fiorentino was suppressed (to Diocese of Lucera) |
| 1413.01.13 | Abbacy nullius of Nardò was promoted as Diocese of Nardò (without ecclesiastical province) |
| 1419.05.10 | Diocese of Firenze was promoted as Metropolitan Archdiocese of Firenze (with suffragan sees Fiesole and Pistoia) |
| 1420.02.12 | Diocese of Suelli was suppressed (to Metropolitan Archdiocese of Cagliari) |
| 1422.10.19 | Diocese of Ancona was renamed as Diocese of Ancona e Umana (gained territory from the suppressed Diocese of Numana) |
| 1422.10.19 | Diocese of Numana was suppressed (to Diocese of Ancona e Umana) |
| 1424 | Diocese of Salpi was suppressed (to Metropolitan Archdiocese of Trani) |
| 1425 | Territorial Abbacy of San Paolo fuori le Mura was established |
| 1425 | Diocese of Tortiboli was suppressed (to Diocese of Lucera) |
| 1426 | Diocese of Valva lost territory to Diocese of L’Aquila |
| 1429 | Diocese of Nuceria was renamed as Diocese of Nocera de’ Pagani |
| 1430 | Metropolitan Archdiocese of Pisa lost territory to Metropolitan Archdiocese of Genova |
| 1435.12.05 | Diocese of Corneto was restored (from Diocese of Tuscanella) |
| 1437.03.20 | Diocese of Cariati was established (from Archdiocese of Rossano and became suffragan of Santa Severina) |
| 1440 | Diocese of Eraclea was suppressed (to Patriarchal See of Grado) |
| 1441 | Metropolitan Archdiocese of Torres was renamed as Metropolitan Archdiocese of Sassari |
| 1449 | Archpresbyterate nullius of Lanciano was established (from Diocese of Chieti) |
| 1451.10.08 | Diocese of Castello was suppressed (to establish Patriarchal See of Venezia) |
| 1451.10.08 | Patriarchal See of Grado was suppressed (to establish Patriarchal See of Venezia) |
| 1451.10.08 | Patriarchal See of Venezia was established (from the suppressed Patriarchal See of Grado and Diocese of Castello and with suffragan sees Belluno, Chioggia, Cittanova, Feltre and Padova) |
| 1452 | Diocese of Montepeloso was restored (from Diocese of Andria and without ecclesiastical province) |
| 1452.07.28 | Diocese of Porto e Santa Rufina was renamed as Diocese of Porto (lost territory to establish Diocese of Santa Rufina) |
| 1452.07.28 | Diocese of Santa Rufina was restored (from Diocese of Porto e Santa Rufina) |
| 1454.03.22 | Diocese of Porto was renamed as Diocese of Porto e Santa Rufina (gained territory from the suppressed Diocese of Santa Rufina) |
| 1454.03.22 | Diocese of Santa Rufina was suppressed (to Diocese of Porto e Santa Rufina) |
| 1455.04.30 | Archpresbyterate nullius of Cerignola was established (from Archpresbyterate nullius of Canosa) |
| 1459.04.23 | Diocese of Siena was promoted as Metropolitan Archdiocese of Siena (with suffragan sees Chiusi, Grosseto, Massa Marittima e Populonia and Sovana) |
| 1462.08.13 | Diocese of Montalcino was established (from Diocese of Arezzo, Diocese of Chiusi and Diocese of Grosseto) |
| 1462.08.13 | Diocese of Pienza was established (from Diocese of Arezzo and Diocese of Chiusi) |
| 1463.09.05 | Provostry nullius of Santo Stefano di Prato was established (from Diocese of Pistoia and without ecclesiastical province) |
| 1465.07.21 | Diocese of Luni was renamed as Diocese of Luni–Sarzana |
| 1466 | Diocese of Equilio was suppressed (to Patriarchal See of Venezia) |
| 1471 | Archpresbyterate nullius of Guastalla was established (from Diocese of Reggio Emilia) |
| 1474.04.18 | Diocese of Casale Monferrato was established (from Diocese of Asti and Diocese of Vercelli and became suffragan of Milano) |
| 1480 | Collegiate nullius of Montepulciano was established (from Diocese of Arezzo) |
| 1495.06.21 | Diocese of Sabina was established (from Diocese of Vescovìo and became suffragan of Roma) |
| 1495.09.11 | Diocese of Galtellì was suppressed (to Metropolitan Archdiocese of Cagliari) |
| 1495.09.18 | Diocese of Vescovìo was suppressed (to Diocese of Sabina) |
| 1502.01.24 | Diocese of Città Ducale was established (from Diocese of Rieti) |
| 1503.11.26 | Diocese of Iglesias was established (from the suppressed Diocese of Sulci and became suffragan of Cagliari) |
| 1503.11.26 | Diocese of Sulci was suppressed (to establish Diocese of Iglesias) |
| 1503.12.08 | Diocese of Alghero was established (from Metropolitan Archdiocese of Sassari, from the suppressed Diocese of Bisarcio, Diocese of Castro and Diocese of Ottana and became suffragan of Sassari) |
| 1503.12.08 | Diocese of Bisarcio was suppressed (to establish Diocese of Alghero) |
| 1503.12.08 | Diocese of Castro was suppressed (to establish Diocese of Alghero) |
| 1503.12.08 | Diocese of Dolia was suppressed (to Metropolitan Archdiocese of Cagliari) |
| 1503.12.08 | Diocese of Ottana was suppressed (to establish Diocese of Alghero) |
| 1503.12.08 | Diocese of Ploaghe was suppressed (to Metropolitan Archdiocese of Sassari) |
| 1503.12.08 | Diocese of Santa Giusta was suppressed (to Metropolitan Archdiocese of Oristano) |
| 1503.12.08 | Diocese of Sorres was suppressed (to Metropolitan Archdiocese of Sassari) |
| 1505.11.08 | Diocese of Città Ducale was suppressed (to Diocese of Rieti) |
| 1507 | Apostolic Administration of Loreto was established (from Diocese of Recanati) |
| 1508.10.17 | Diocese of Città Ducale was restored (from Diocese of Rieti) |
| 1511.10.29 | Diocese of Saluzzo was established (from Diocese of Alba, Diocese of Asti and Diocese of Torino and without ecclesiastical province) |
| 1512.02.01 | Diocese of Modena lost territory to Archpresbyterate nullius of Santa Maria Assunta di Carpi |
| 1512.02.01 | Abbacy nullius of Nonantola lost territory to Archpresbyterate nullius of Santa Maria Assunta di Carpi |
| 1513 | Territorial Abbacy of Santissima Trinità di Cava de’ Tirreni was established (from Diocese of Cava) |
| 1515.05.01 | Diocese of Reggio Emilia lost territory to Archpresbyterate nullius of Santa Maria Assunta di Carpi |
| 1515.05.21 | Diocese of Torino was promoted as Metropolitan Archdiocese of Torino (with suffragan sees Asti, Ivrea and Mondovì) |
| 1515.06.27 | Diocese of Chieti lost territory to Diocese of Lanciano |
| 1515.06.27 | Archpresbyterate nullius of Lanciano was promoted as Diocese of Lanciano (gained territory from Diocese of Chieti and without ecclesiastical province) |
| 1515.09.22 | Diocese of Arezzo lost territory to Abbacy nullius of Sansepolcro |
| 1515.09.22 | Diocese of Città di Castello lost territory to Abbacy nullius of Sansepolcro |
| 1519.04.15 | Territorial Prelature of Pescia was established (from Diocese of Lucca and Diocese of Pistoia and without ecclesiastical province) |
| 1520.09.17 | Abbacy nullius of Sansepolcro was promoted as Diocese of Sansepolcro (became suffragan of Firenze) |
| 1523 | Diocese of Salpi was restored (from Metropolitan Archdiocese of Trani) |
| 1525.06.19 | Diocese of Campagna was established (from Metropolitan Archdiocese of Salerno and Diocese of Satriano and became suffragan of Salerno) |
| 1526.06.01 | Diocese of Chieti was promoted as Metropolitan Archdiocese of Chieti (with suffragan sees Atri, Lanciano and Penne) |
| 1530.03.14 | Diocese of Vigevano was established (from Diocese of Novara and Diocese of Pavia and became suffragan of Milano) |
| 1531.03.06 | Diocese of Giffoni was established (from Metropolitan Archdiocese of Salerno and Diocese of Acerno) |
| 1532.06.28 | Diocese of Giffoni was suppressed (to Metropolitan Archdiocese of Salerno and Diocese of Acerno) |
| 1534 | Diocese of Sarno lost territory to Diocese of Nola |
| 1535 | Diocese of Pavia lost territory to Diocese of Vigevano |
| 1537 | Diocese of Tusculum–Frascati was renamed as Diocese of Frascati |
| 1545.08.08 | Diocese of Anglona was renamed as Diocese of Anglona–Tursi |
| 1547.04.22 | Diocese of Salpi was suppressed (to Metropolitan Archdiocese of Trani) |
| 1561.01.09 | Diocese of Lanciano was promoted as Metropolitan Archdiocese of Lanciano |
| 1561.11.10 | Diocese of Arezzo lost territory to Diocese of Montepulciano |
| 1561.11.10 | Diocese of Chiusi lost territory to Diocese of Montepulciano |
| 1561.11.10 | Collegiate nullius of Montepulciano was promoted as Diocese of Montepulciano (gained territory from Diocese of Arezzo and Diocese of Chiusi and without ecclesiastical province) |
| 1563.03.17 | Diocese of Gallese was restored (from Diocese of Civita Castellana) |
| 1563.06.04 | Diocese of Urbino was promoted as Metropolitan Archdiocese of Urbino (with suffragan sees Cagli, Gubbio, Montefeltro, Pesaro and Senigallia) |
| 1567 | Diocese of Lesina was suppressed (to Diocese of Larino) |
| 1569.09.16 | Diocese of Gallese was suppressed (to Diocese of Civita Castellana) |
| 1570.10.20 | Diocese of Ortona was restored (from Metropolitan Archdiocese of Lanciano and became suffragan of Chieti) |
| 1571.08.01 | Abbacy nullius of Farfa lost territory to Diocese of Ascoli Piceno |
| 1571.08.01 | Diocese of Ripatransone was established (from Diocese of Ascoli Piceno, Diocese of Fermo, Diocese of Teramo and Abbacy nullius of Farfa) |
| 1571.11.27 | Diocese of San Leone was suppressed (to Metropolitan Archdiocese of Santa Severina) |
| 1580.02.21 | Diocese of Civitate was suppressed (to establish Diocese of San Severo) |
| 1580.02.21 | Diocese of Dragonara was suppressed (to establish Diocese of San Severo) |
| 1580.02.21 | Diocese of San Severo was established (from the suppressed Diocese of Civitate and Diocese of Dragonara and became suffragan of Benevento) |
| 1580.04.11 | Diocese of Crema was established (from Diocese of Cremona, Diocese of Lodi and Diocese of Piacenza and became suffragan of Milano) |
| 1582.12.10 | Diocese of Bologna was promoted as Metropolitan Archdiocese of Bologna (with suffragan sees Cervia, Crema, Imola, Modena, Parma, Piacenza and Reggio Emilia) |
| 1585.11.05 | Archpresbyterate nullius of Guastalla was promoted as Abbacy nullius of San Pietro Apostolo di Guastalla |
| 1586 | Diocese of Osimo lost territory to Diocese of Recanati |
| 1586.03.17 | Apostolic Administration of Loreto was promoted as Diocese of Loreto (gained territory from Diocese of Macerata, gained territory from the suppressed Diocese of Recanati and without ecclesiastical province) |
| 1586.03.17 | Diocese of Macerata lost territory to Diocese of Loreto |
| 1586.03.17 | Diocese of Recanati was suppressed (to Diocese of Loreto) |
| 1586.07.17 | Diocese of Capaccio was renamed as Diocese of Capaccio–Diano |
| 1586.11.24 | Diocese of Montalto was established (from Diocese of Ascoli Piceno, Diocese of Fermo, Diocese of Ripatransone and Diocese of Teramo and without ecclesiastical province) |
| 1586.11.26 | Diocese of San Severino was restored (from Diocese of Camerino) |
| 1586.11.26 | Diocese of Spoleto lost territory to Diocese of Camerino |
| 1586.12.10 | Diocese of Tolentino was restored (from Diocese of Camerino) |
| 1588 | Diocese of Camerino lost territory to Diocese of Macerata |
| 1589.05.24 | Diocese of Fermo was promoted as Metropolitan Archdiocese of Fermo (with suffragan sees Macerata, Montalto, Ripatransone, San Severino and Tolentino) |
| 1591.05.08 | Metropolitan Archdiocese of Brindisi–Oria was renamed as Metropolitan Archdiocese of Brindisi (lost territory to establish Diocese of Oria) |
| 1591.05.08 | Diocese of Oria was established (from Metropolitan Archdiocese of Brindisi–Oria and became suffragan of Taranto) |
| 1592.02.09 | Diocese of Recanati was restored (from Diocese of Loreto) |
| 1592.04.15 | Diocese of Fossano was established (from Metropolitan Archdiocese of Torino and Diocese of Asti and became suffragan of Torino) |
| 1592.06.05 | Collegiate nullius of Colle di Val d’Elsa was promoted as Diocese of Colle di Val d’Elsa (gained territory from Metropolitan Archdiocese of Firenze, Metropolitan Archdiocese of Siena, Diocese of Fiesole and Diocese of Volterra and became suffragan of Firenze) |
| 1592.06.05 | Diocese of Fiesole lost territory to Diocese of Colle di Val d’Elsa |
| 1592.06.05 | Metropolitan Archdiocese of Firenze lost territory to Diocese of Colle di Val d’Elsa |
| 1592.06.05 | Metropolitan Archdiocese of Siena lost territory to Diocese of Colle di Val d’Elsa |
| 1592.06.05 | Diocese of Volterra lost territory to Diocese of Colle di Val d’Elsa |
| 1600.05.12 | Diocese of Campli was established (from Diocese of Montalto and Diocese of Teramo) |
| 1600.09.25 | Diocese of Città della Pieve was restored (from Diocese of Chiusi) |
| 1601.02.12 | Provostry nullius of Borgo San Donnino was promoted as Diocese of Borgo San Donnino (gained territory from Diocese of Cremona and without ecclesiastical province) |
| 1601.02.12 | Diocese of Cremona lost territory to Diocese of Borgo San Donnino |
| 1622.12.05 | Diocese of San Miniato was established (from Diocese of Lucca and became suffragan of Firenze) |
| 1626 | Abbacy nullius of San Giovanni in Venere lost territory to Metropolitan Archdiocese of Chieti |
| 1629.03.07 | Papal See of Roma lost territory to Diocese of Porto e Santa Rufina |
| 1635.02.08 | Diocese of Sant’Angelo in Vado was restored (from Abbacy nullius of San Cristoforo di Castel Durante) |
| 1635.02.08 | Abbacy nullius of San Cristoforo di Castel Durante was promoted as Diocese of Urbania (lost territory to establish Diocese of Sant’Angelo in Vado) |
| 1636.10.20 | Diocese of Città di Castello lost territory to Diocese of Sant’Angelo in Vado |
| 1636.10.20 | Metropolitan Archdiocese of Urbino lost territory to Diocese of Sant’Angelo in Vado |
| 1638 | Diocese of Tivoli lost territory to Territorial Abbacy of Subiaco |
| 1639.07.21 | Diocese of Anagni lost territory to Territorial Abbacy of Subiaco |
| 1649.09.13 | Diocese of Acquapendente was established (from Diocese of Orvieto, from the suppressed Diocese of Castro del Lazio and without ecclesiastical province) |
| 1649.09.13 | Diocese of Castro del Lazio was suppressed (to establish Diocese of Acquapendente) |
| 1653 | Abbacy nullius of Pomposa was suppressed |
| 1653.09.22 | Provostry nullius of Santo Stefano di Prato was promoted as Diocese of Prato (became suffragan of Firenze) |
| 1656 | Diocese of Ariano lost territory to Metropolitan Archdiocese of Benevento |
| 1696 | Archpresbyterate nullius of Acquaviva delle Fonti was suppressed (to Metropolitan Archdiocese of Bari e Canosa) |
| 1700 | Abbacy nullius of Asola was established |
| 1717.08.13 | Abbacy nullius of Santissima Trinità di Mileto was suppressed (to Diocese of Mileto) |
| 1725.06.23 | Diocese of Pontecorvo was established (from Diocese of Aquino and without ecclesiastical province) |
| 1725.08.19 | Diocese of Cingoli was restored (from Diocese of Osimo) |
| 1726.09.11 | Diocese of Lucca was promoted as Archdiocese of Lucca |
| 1727 | Diocese of San Miniato lost territory to Diocese of Pescia |
| 1727.03.17 | Archdiocese of Lucca lost territory to Diocese of Pescia |
| 1727.03.17 | Territorial Prelature of Pescia was promoted as Diocese of Pescia (gained territory from Archdiocese of Lucca) |
| 1728.11.15 | Diocese of Fabriano was established (from Diocese of Camerino) |
| 1731 | Archpresbyterate nullius of Canosa was promoted as Territorial Prelature of Canosa |
| 1732.06.10 | Ordinariate of Italia continentale (Italo-Albanese Rite) was established |
| 1735.07.27 | Diocese of Ferrara was promoted as Archdiocese of Ferrara |
| 1748.12.23 | Diocese of Pinerolo was established (from Metropolitan Archdiocese of Torino and Abbacy nullius of Santa Maria ad Abbadia Alpina and became suffragan of Torino) |
| 1749.11.26 | Diocese of Terlizzi was established (from Diocese of Giovinazzo and became suffragan of Bari e Canosa) |
| 1751.07.06 | Patriarchal See of Aquileia was suppressed (to establish Metropolitan Archdiocese of Gorizia and Metropolitan Archdiocese of Udine) |
| 1751.07.06 | Metropolitan Archdiocese of Gorizia was established (from the suppressed Patriarchal See of Aquileia and with suffragan sees Koper, Ljubljana and Trieste) |
| 1751.07.06 | Metropolitan Archdiocese of Udine was established (from the suppressed Patriarchal See of Aquileia and with suffragan sees Ceneda, Concordia, Poreč, Pula, Treviso, Verona and Vicenza) |
| 1755 | Titular Episcopal See of Sinita was restored |
| 1765.01.18 | Territorial Abbacy of Monte Oliveto Maggiore was established (from Diocese of Arezzo) |
| 1767 | Diocese of Ales exchanged territory with Metropolitan Archdiocese of Cagliari |
| 1767 | Metropolitan Archdiocese of Cagliari exchanged territory with Diocese of Ales |
| 1768 | Diocese of Alba lost territory to Diocese of Mondovì |
| 1768 | Diocese of Asti lost territory to Diocese of Mondovì |
| 1770.10.13 | Diocese of Ischia lost territory to Diocese of Gaeta |
| 1772.04.29 | Diocese of Spoleto lost territory to Diocese of Foligno |
| 1772.06.01 | Diocese of Biella was established (from Diocese of Vercelli and became suffragan of Torino) |
| 1772.06.15 | Diocese of Chiusi lost territory to Diocese of Montalcino |
| 1772.06.15 | Diocese of Pienza lost territory to Metropolitan Archdiocese of Siena and Diocese of Montalcino |
| 1772.08.03 | Abbacy nullius of San Pietro di Novalesa lost territory to Diocese of Susa |
| 1772.08.03 | Abbacy nullius of San Giusto di Susa was promoted as Diocese of Susa (gained territory from Metropolitan Archdiocese of Torino and Abbacy nullius of San Pietro di Novalesa and became suffragan of Torino) |
| 1772.08.03 | Metropolitan Archdiocese of Torino lost territory to Diocese of Susa |
| 1777 | Diocese of Rimini lost territory to Diocese of Cesena |
| 1779.07.21 | Diocese of Galtellì–Nuoro was restored (from Metropolitan Archdiocese of Cagliari, Metropolitan Archdiocese of Oristano and Diocese of Alghero and became suffragan of Cagliari) |
| 1779.12.01 | Archpresbyterate nullius of Santa Maria Assunta di Carpi was promoted as Diocese of Carpi (became suffragan of Bologna) |
| 1782.09.18 | Diocese of Volterra lost territory to Diocese of Colle di Val d’Elsa |
| 1784 | Metropolitan Archdiocese of Bologna lost territory to Diocese of Pistoia |
| 1784 | Metropolitan Archdiocese of Gorizia lost territory to Diocese of Trieste |
| 1784 | Diocese of Montefeltro lost territory to Diocese of Sansepolcro |
| 1784 | Diocese of Pistoia lost territory to Diocese of Pescia |
| 1784 | Diocese of Trieste lost territory to Diocese of Cittanova, Diocese of Koper and Diocese of Ljubljana |
| 1784.02.06 | Ordinariate of Silicia (Italo-Albanese Rite) was established |
| 1785.04 | Diocese of Acquapendente exchanged territory with Diocese of Sovana |
| 1785.04 | Diocese of Sovana exchanged territory with Diocese of Acquapendente |
| 1785.07.08 | Diocese of Matelica was restored (from Diocese of Camerino) |
| 1786 | Diocese of Feltre lost territory to Diocese of Trento |
| 1787 | Diocese of Bergamo exchanged territory with Metropolitan Archdiocese of Milano |
| 1787 | Metropolitan Archdiocese of Gorizia lost territory to Diocese of Gurk |
| 1787 | Metropolitan Archdiocese of Milano (Ambrosian Rite) exchanged territory with Diocese of Bergamo |
| 1787 | Diocese of Padova lost territory to Diocese of Trento |
| 1787.12.17 | Diocese of Camerino was promoted as Archdiocese of Camerino |
| 1788.03.08 | Metropolitan Archdiocese of Gorizia was suppressed (to Metropolitan Archdiocese of Ljubljana and to establish Diocese of Gradisca) |
| 1788.03.08 | Diocese of Gradisca was established (from the suppressed Metropolitan Archdiocese of Gorizia, Diocese of Pedena and Diocese of Trieste and became suffragan of Ljubljana) |
| 1788.03.08 | Diocese of Trieste was suppressed (to establish Diocese of Gradisca) |
| 1789 | Diocese of Pienza lost territory to Diocese of Montalcino |
| 1789.01.16 | Archpresbyterate nullius of Acquaviva delle Fonti was restored (from Metropolitan Archdiocese of Bari e Canosa) |
| 1789.07.18 | Archdiocese of Lucca exchanged territory with Metropolitan Archdiocese of Pisa |
| 1789.07.18 | Metropolitan Archdiocese of Pisa exchanged territory with Archdiocese of Lucca |
| 1791 | Diocese of Massa Marittima e Populonia lost territory to Diocese of Brugnato |
| 1791.09.12 | Diocese of Gorizia e Gradisca was restored (from the suppressed Diocese of Gradisca and became suffragan of Ljubljana) |
| 1791.09.12 | Diocese of Gradisca was suppressed (to establish Diocese of Gorizia e Gradisca and Diocese of Trieste) |
| 1791.09.12 | Diocese of Trieste was restored (from the suppressed Diocese of Gradisca and became suffragan of Ljubljana) |
| 1792.09.07 | Abbacy nullius of Santa Maria di Vangadizza was suppressed (to Diocese of Adria) |
| 1794 | Diocese of Pinerolo lost territory to Diocese of Susa |
| 1794 | Abbacy nullius of Santa Maria di Sesto was suppressed (to Diocese of Concordia) |
| 1797 | Diocese of Ventimiglia lost territory to Diocese of Nice |
| 1797.07.04 | Diocese of Pontremoli was established (from Diocese of Brugnato and Diocese of Luni–Sarzana and became suffragan of Pisa) |
| 1798 | Metropolitan Archdiocese of Sassari lost territory to Diocese of Alghero |
| 1798.09.18 | Diocese of Pontremoli lost territory to Metropolitan Archdiocese of Pisa |
| 1801.06.01 | Diocese of Fossano was suppressed (to Diocese of Mondovì) |
| 1803 | Diocese of Bertinoro was suppressed (to Metropolitan Archdiocese of Ravenna) |
| 1803 | Diocese of Brugnato lost territory to Diocese of Ajaccio |
| 1803 | Archdiocese of Ferrara was promoted as Metropolitan Archdiocese of Ferrara (with suffragan sees Adria, Comacchio, Mantova and Verona) |
| 1803 | Metropolitan Archdiocese of Genova lost territory to Diocese of Ajaccio |
| 1803 | Diocese of Grosseto lost territory to Diocese of Ajaccio |
| 1803 | Diocese of Massa Marittima e Populonia lost territory to Diocese of Ajaccio |
| 1803.03.09 | Diocese of Bisarcio was restored (from Metropolitan Archdiocese of Sassari and Diocese of Alghero and became suffragan of Sassari) |
| 1803.03.09 | Diocese of Bosa lost territory to Diocese of Alghero |
| 1803.03.09 | Metropolitan Archdiocese of Oristano lost territory to Diocese of Bosa |
| 1803.06.01 | Diocese of Alba was suppressed (to Diocese of Asti) |
| 1803.06.01 | Diocese of Alessandria was suppressed (to Diocese of Casale Monferrato) |
| 1803.06.01 | Diocese of Aosta was suppressed (to Diocese of Ivrea) |
| 1803.06.01 | Diocese of Biella was suppressed (to Diocese of Vercelli) |
| 1803.06.01 | Diocese of Bobbio was suppressed (to Diocese of Casale Monferrato) |
| 1803.06.01 | Diocese of Pinerolo was suppressed (to Diocese of Saluzzo) |
| 1803.06.01 | Diocese of Susa was suppressed (to Metropolitan Archdiocese of Torino) |
| 1803.06.01 | Diocese of Tortona was suppressed (to Diocese of Casale Monferrato) |
| 1803.06.07 | Abbacy nullius of Sacra di San Michele was suppressed (to Metropolitan Archdiocese of Torino) |
| 1803.09.01 | Diocese of Albenga lost territory to Diocese of Mondovì |
| 1805 | Abbacy nullius of Santa Maria ad Abbadia Alpina was suppressed (to Diocese of Saluzzo) |
| 1805.12.20 | Diocese of Gallese was restored (from Diocese of Civita Castellana) |
| 1806.09.25 | Diocese of Livorno was established (from Metropolitan Archdiocese of Pisa and became suffragan of Pisa) |
| 1809.01.02 | Diocese of Pavia lost territory to Diocese of Piacenza |
| 1810 | Diocese of Brixen lost territory to Diocese of Belluno |
| 1813 | Diocese of Reggio Emilia lost territory to Diocese of Mantova |
| 1816.09.12 | Diocese of Caltagirone was established (from Metropolitan Archdiocese of Messina and Diocese of Catania, gained territory from Diocese of Siracusa and became suffragan of Monreale) |
| 1816.09.12 | Diocese of Siracusa lost territory to Diocese of Caltagirone |
| 1817 | Diocese of Bertinoro was restored (from Metropolitan Archdiocese of Ravenna) |
| 1817.02.08 | Diocese of Treia was restored (from Archdiocese of Camerino) |
| 1817.03.17 | Diocese of Nicosia was established (from Metropolitan Archdiocese of Messina and Diocese of Catania and became suffragan of Messina) |
| 1817.07.03 | Diocese of Piazza Armerina was established (from Diocese of Catania and became suffragan of Monreale) |
| 1817.07.17 | Diocese of Alba was restored (from Diocese of Asti and Diocese of Mondovì and became suffragan of Torino) |
| 1817.07.17 | Diocese of Alessandria was restored (from Diocese of Casale Monferrato and became suffragan of Vercelli) |
| 1817.07.17 | Diocese of Aosta was restored (from Diocese of Ivrea and became suffragan of Chambéry) |
| 1817.07.17 | Diocese of Asti lost territory to Diocese of Mondovì |
| 1817.07.17 | Diocese of Biella was restored (from Diocese of Vercelli and became suffragan of Vercelli) |
| 1817.07.17 | Diocese of Casale Monferrato lost territory to Diocese of Acqui |
| 1817.07.17 | Diocese of Cuneo was established (from Diocese of Mondovì and became suffragan of Torino) |
| 1817.07.17 | Diocese of Fossano was restored (from Diocese of Mondovì and became suffragan of Torino) |
| 1817.07.17 | Metropolitan Archdiocese of Milano (Ambrosian Rite) lost territory to Diocese of Novara and Diocese of Vigevano |
| 1817.07.17 | Diocese of Mondovì lost territory to Metropolitan Archdiocese of Torino and Diocese of Saluzzo |
| 1817.07.17 | Diocese of Novara lost territory to Diocese of Vigevano |
| 1817.07.17 | Diocese of Pavia lost territory to Diocese of Vigevano |
| 1817.07.17 | Diocese of Pinerolo was restored (from Diocese of Saluzzo and became suffragan of Torino) |
| 1817.07.17 | Diocese of Susa was restored (from Metropolitan Archdiocese of Torino and became suffragan of Torino) |
| 1817.07.17 | Diocese of Tortona was restored (from Diocese of Casale Monferrato, Diocese of Pavia and Diocese of Piacenza and became suffragan of Genova) |
| 1817.07.17 | Diocese of Vercelli was promoted as Metropolitan Archdiocese of Vercelli (with suffragan sees Alessandria, Biella and Casale Monferrato and lost territory to establish Diocese of Biella) |
| 1817.10.29 | Diocese of Alba lost territory to Diocese of Mondovì |
| 1817.11.23 | Diocese of Bobbio was restored (from Diocese of Casale Monferrato and became suffragan of Genova) |
| 1818 | Diocese of Bobbio lost territory to Diocese of Tortona |
| 1818.01.31 | Diocese of Gubbio lost territory to Diocese of Cagli |
| 1818.01.31 | Diocese of Nocera Umbra lost territory to Diocese of Cagli |
| 1818.01.31 | Abbacy nullius of Nonantola lost territory to Diocese of Cagli |
| 1818.05.01 | Diocese of Adria exchanged territory with Metropolitan Archdiocese of Ferrara |
| 1818.05.01 | Diocese of Belluno lost territory to Diocese of Treviso |
| 1818.05.01 | Diocese of Caorle was suppressed (to Patriarchal See of Venezia) |
| 1818.05.01 | Diocese of Concordia exchanged territory with Metropolitan Archdiocese of Udine |
| 1818.05.01 | Diocese of Feltre lost territory to Diocese of Padova and Diocese of Trento |
| 1818.05.01 | Metropolitan Archdiocese of Ferrara exchanged territory with Diocese of Adria |
| 1818.05.01 | Diocese of Padova exchanged territory with Diocese of Vicenza |
| 1818.05.01 | Metropolitan Archdiocese of Ravenna lost territory to Diocese of Adria |
| 1818.05.01 | Diocese of Torcello was suppressed (to Patriarchal See of Venezia) |
| 1818.05.01 | Metropolitan Archdiocese of Udine was demoted as Diocese of Udine (gained territory from Patriarchal See of Venezia, lost territory to Diocese of Ceneda and Diocese of Treviso, exchanged territory with Diocese of Concordia and became suffragan of Venezia) |
| 1818.05.01 | Patriarchal See of Venezia lost territory to Diocese of Ceneda, Diocese of Gorizia e Gradisca and Diocese of Udine |
| 1818.05.01 | Diocese of Verona lost territory to Diocese of Padova |
| 1818.05.01 | Diocese of Vicenza exchanged territory with Diocese of Padova |
| 1818.06.27 | Archpresbyterate nullius of Acquaviva delle Fonti was suppressed (to Metropolitan Archdiocese of Bari e Canosa) |
| 1818.06.27 | Diocese of Alessano was suppressed (to Diocese of Ugento) |
| 1818.06.27 | Diocese of Alife was suppressed (to Diocese of Telese) |
| 1818.06.27 | Metropolitan Archdiocese of Amalfi was demoted as Archdiocese of Amalfi (gained territory from the suppressed Diocese of Minori, Diocese of Ravello and Diocese of Scala and without ecclesiastical province) |
| 1818.06.27 | Diocese of Belcastro was suppressed (to Metropolitan Archdiocese of Santa Severina) |
| 1818.06.27 | Diocese of Bitetto was suppressed (to Metropolitan Archdiocese of Bari e Canosa) |
| 1818.06.27 | Diocese of Caiazzo was suppressed (to Diocese of Caserta) |
| 1818.06.27 | Diocese of Campli was suppressed (to Diocese of Teramo) |
| 1818.06.27 | Diocese of Canne was suppressed (to Metropolitan Archdiocese of Trani) |
| 1818.06.27 | Territorial Prelature of Canosa was suppressed (to Diocese of Andria) |
| 1818.06.27 | Diocese of Capri was suppressed (to Metropolitan Archdiocese of Sorrento) |
| 1818.06.27 | Diocese of Carinola was suppressed (to Diocese of Sessa Aurunca) |
| 1818.06.27 | Diocese of Castro was suppressed (to Metropolitan Archdiocese of Otranto) |
| 1818.06.27 | Diocese of Cerenzia was suppressed (to Diocese of Cariati) |
| 1818.06.27 | Diocese of Città Ducale was suppressed (to Diocese of L’Aquila) |
| 1818.06.27 | Metropolitan Archdiocese of Cosenza was demoted as Archdiocese of Cosenza (without ecclesiastical province) |
| 1818.06.27 | Diocese of Fondi was suppressed (to Diocese of Gaeta) |
| 1818.06.27 | Diocese of Frigento was suppressed (to Diocese of Avellino) |
| 1818.06.27 | Diocese of Giovinazzo was suppressed (to Diocese of Molfetta) |
| 1818.06.27 | Diocese of Guardialfiera was suppressed (to Diocese of Termoli) |
| 1818.06.27 | Diocese of Isola was suppressed (to Diocese of Crotone) |
| 1818.06.27 | Diocese of Lavello was suppressed (to Diocese of Venosa) |
| 1818.06.27 | Diocese of Lettere–Gragnano was suppressed (to Diocese of Castellammare di Stabia) |
| 1818.06.27 | Diocese of Martirano was suppressed (to Diocese of Nicastro) |
| 1818.06.27 | Diocese of Massa Lubrense was suppressed (to Metropolitan Archdiocese of Sorrento) |
| 1818.06.27 | Archdiocese of Matera was suppressed (to Metropolitan Archdiocese of Acerenza) |
| 1818.06.27 | Diocese of Minervino was suppressed (to Diocese of Andria) |
| 1818.06.27 | Diocese of Minori was suppressed (to Archdiocese of Amalfi) |
| 1818.06.27 | Diocese of Montecorvino was suppressed (to Diocese of Lucera) |
| 1818.06.27 | Diocese of Montemarano was suppressed (to Diocese of Nusco) |
| 1818.06.27 | Diocese of Monteverde was suppressed (to Metropolitan Archdiocese of Conza and Diocese of Sant’Angelo dei Lombardi) |
| 1818.06.27 | Diocese of Mottola was suppressed (to Diocese of Castellaneta) |
| 1818.06.27 | Metropolitan Archdiocese of Nazareth in Barletta was suppressed (to Metropolitan Archdiocese of Trani) |
| 1818.06.27 | Diocese of Nocera de’ Pagani was suppressed (to Diocese of Cava) |
| 1818.06.27 | Diocese of Ortona was suppressed (to Metropolitan Archdiocese of Lanciano) |
| 1818.06.27 | Diocese of Ostuni was suppressed (to Metropolitan Archdiocese of Brindisi) |
| 1818.06.27 | Diocese of Ravello was suppressed (to Archdiocese of Amalfi) |
| 1818.06.27 | Diocese of Sarno was suppressed (to Diocese of Cava) |
| 1818.06.27 | Diocese of Satriano was suppressed (to Metropolitan Archdiocese of Conza and Diocese of Campagna) |
| 1818.06.27 | Diocese of Scala was suppressed (to Archdiocese of Amalfi) |
| 1818.06.27 | Diocese of Strongoli was suppressed (to Diocese of Cariati) |
| 1818.06.27 | Diocese of Terlizzi was suppressed (to Diocese of Molfetta) |
| 1818.06.27 | Diocese of Trevico was suppressed (to Diocese of Lacedonia) |
| 1818.06.27 | Diocese of Umbriatico was suppressed (to Diocese of Cariati) |
| 1818.06.27 | Diocese of Venafro was suppressed (to Diocese of Isernia) |
| 1818.06.27 | Diocese of Vulturara was suppressed (to Diocese of Lucera) |
| 1818.06.28 | Diocese of Vico Equense was suppressed (to Metropolitan Archdiocese of Sorrento) |
| 1818.07.27 | Diocese of Polignano was suppressed (to Diocese of Monopoli) |
| 1818.09.12 | Abbacy nullius of Asola was suppressed (to Diocese of Brescia and Diocese of Mantova) |
| 1819.01.18 | Diocese of Pergola was established (from Diocese of Cagli) |
| 1819.03.09 | Diocese of Adria exchanged territory with Diocese of Padova |
| 1819.03.09 | Diocese of Padova exchanged territory with Diocese of Adria |
| 1819.06.14 | Archpresbyterate nullius of Cerignola was promoted as Diocese of Cerignola (became suffragan of Benevento) |
| 1820.12.14 | Diocese of Alife was restored (from Diocese of Telese) |
| 1821 | Diocese of Reggio Emilia lost territory to Diocese of Carpi |
| 1821.05.14 | Diocese of Ostuni was restored (from Metropolitan Archdiocese of Brindisi and became suffragan of Brindisi) |
| 1821.09.15 | Diocese of Norcia was restored (from Diocese of Spoleto and without ecclesiastical province) |
| 1821.09.15 | Diocese of Spoleto was promoted as Archdiocese of Spoleto (lost territory to establish Diocese of Norcia) |
| 1822 | Diocese of Carpi lost territory to Diocese of Modena |
| 1822 | Diocese of Novara lost territory to Diocese of Sion |
| 1822.02.18 | Diocese of Luni–Sarzana lost territory to Diocese of Massa Carrara |
| 1822.02.18 | Abbacy nullius of Massa Carrara was promoted as Diocese of Massa Carrara (gained territory from Diocese of Luni–Sarzana and became suffragan of Pisa) |
| 1822.07.03 | Archdiocese of Lucca lost territory to Diocese of Massa Carrara |
| 1822.11.09 | Archdiocese of Matera was restored (from Metropolitan Archdiocese of Acerenza) |
| 1824 | Metropolitan Archdiocese of Messina lost territory to Diocese of Patti |
| 1824.11.08 | Diocese of Ogliastra was established (from Metropolitan Archdiocese of Cagliari and became suffragan of Cagliari) |
| 1825 | Diocese of Agrigento lost territory to Metropolitan Archdiocese of Palermo |
| 1825 | Diocese of Cefalù lost territory to Metropolitan Archdiocese of Palermo |
| 1825.12.10 | Diocese of Civitavecchia was restored (from Diocese of Tuscanella) |
| 1828.09.13 | Abbacy nullius of San Pietro Apostolo di Guastalla was promoted as Diocese of Guastalla (gained territory from Diocese of Parma and without ecclesiastical province) |
| 1828.09.13 | Diocese of Parma lost territory to Diocese of Guastalla and Diocese of Reggio Emilia |
| 1829 | Diocese of Novara exchanged territory with Diocese of Vigevano |
| 1829 | Diocese of Vigevano exchanged territory with Diocese of Novara |
| 1830.07.27 | Diocese of Gorizia e Gradisca was promoted as Metropolitan Archdiocese of Gorizia e Gradisca (with suffragan sees Koper, Krk, Ljubljana, Poreč i Pula and Trieste) |
| 1831.06.20 | Diocese of Albenga lost territory to Diocese of Ventimiglia |
| 1833.12.07 | Diocese of Nocera de’ Pagani was restored (from Diocese of Cava and became suffragan of Salerno) |
| 1833.12.07 | Diocese of Sarno was restored (from Diocese of Cava and became suffragan of Salerno) |
| 1834.02.19 | Diocese of Ortona was restored (from Metropolitan Archdiocese of Lanciano and became suffragan of Lanciano) |
| 1834.11.19 | Provostry nullius of Atina was suppressed (to Territorial Abbacy of Montecassino) |
| 1836.03.04 | Diocese of Giovinazzo was restored (from Diocese of Molfetta and without ecclesiastical province) |
| 1836.03.04 | Diocese of Terlizzi was restored (from Diocese of Molfetta and without ecclesiastical province) |
| 1838 | Territorial Abbacy of Montecassino lost territory to Diocese of San Marco |
| 1839.08.26 | Diocese of Civita was renamed as Diocese of Civita–Tempio |
| 1841.11.25 | Abbacy nullius of Farfa was suppressed (to Diocese of Rieti and to establish Diocese of Poggio Mirteto) |
| 1841.11.25 | Diocese of Poggio Mirteto was established (from Diocese of Rieti and Diocese of Sabina and from the suppressed Abbacy nullius of Farfa and Abbacy nullius of San Salvatore Maggiore) |
| 1841.11.25 | Diocese of Sabina lost territory to Diocese of Narni and Diocese of Tivoli |
| 1841.11.25 | Abbacy nullius of San Salvatore Maggiore was suppressed (to Diocese of Rieti and to establish Diocese of Poggio Mirteto) |
| 1844.01.11 | Diocese of Sovana was renamed as Diocese of Sovana–Pitigliano |
| 1844.05.15 | Diocese of Noto was established (from Diocese of Siracusa) |
| 1844.05.20 | Diocese of Agrigento lost territory to Metropolitan Archdiocese of Monreale |
| 1844.05.20 | Diocese of Caltagirone exchanged territory with Diocese of Piazza Armerina |
| 1844.05.20 | Diocese of Catania lost territory to Diocese of Caltagirone |
| 1844.05.20 | Diocese of Cefalù exchanged territory with Metropolitan Archdiocese of Palermo and Diocese of Patti |
| 1844.05.20 | Diocese of Mazara del Vallo lost territory to Metropolitan Archdiocese of Monreale |
| 1844.05.20 | Diocese of Nicosia lost territory to Diocese of Patti and Diocese of Piazza Armerina |
| 1844.05.20 | Metropolitan Archdiocese of Palermo exchanged territory with Diocese of Cefalù |
| 1844.05.20 | Diocese of Patti exchanged territory with Diocese of Cefalù |
| 1844.05.20 | Diocese of Piazza Armerina exchanged territory with Diocese of Caltagirone |
| 1844.05.20 | Diocese of Siracusa was promoted as Metropolitan Archdiocese of Siracusa (with suffragan sees Caltagirone, Noto and Piazza Armerina and lost territory to Diocese of Piazza Armerina) |
| 1844.05.25 | Diocese of Caltanissetta was established (from Diocese of Agrigento, Diocese of Cefalù and Diocese of Nicosia and became suffragan of Monreale) |
| 1844.05.31 | Diocese of Trapani was established (from Diocese of Mazara del Vallo and became suffragan of Palermo) |
| 1846 | Diocese of Agrigento lost territory to Metropolitan Archdiocese of Palermo |
| 1846.04.30 | Diocese of Udine lost territory to Diocese of Belluno |
| 1847.03.14 | Diocese of Udine was promoted as Metropolitan Archdiocese of Udine |
| 1848 | Diocese of Albano lost territory to Diocese of Frascati |
| 1848.08.17 | Territorial Prelature of Acquaviva delle Fonti was restored (from Metropolitan Archdiocese of Bari e Canosa and without ecclesiastical province) |
| 1848.08.17 | Archpresbyterate nullius of Altamura was promoted as Territorial Prelature of Altamura (without ecclesiastical province) |
| 1848.12.31 | Diocese of Gaeta was promoted as Archdiocese of Gaeta |
| 1849.12.16 | Diocese of Caiazzo was restored (from Diocese of Caserta and became suffragan of Capua) |
| 1850 | Diocese of Civita Castellana lost territory to Diocese of Viterbo |
| 1850.07.07 | Diocese of Modigliana was established (from Diocese of Bertinoro, Diocese of Faenza, Diocese of Forlì and Diocese of Sarsina and became suffragan of Bologna) |
| 1850.09.05 | Diocese of Sutri lost territory to Diocese of Civitavecchia |
| 1850.09.21 | Diocese of Capaccio–Diano was renamed as Diocese of Capaccio (lost territory to establish Diocese of Diano–Teggiano) |
| 1850.09.21 | Diocese of Diano–Teggiano was established (from Metropolitan Archdiocese of Salerno, Diocese of Capaccio–Diano and Diocese of Cava and became suffragan of Salerno) |
| 1851.07.16 | Diocese of Capaccio was renamed as Diocese of Capaccio–Vallo |
| 1852.06.19 | Diocese of Venafro was restored (from Diocese of Isernia and became suffragan of Capua) |
| 1853.07.23 | Diocese of Vasto was established (from Metropolitan Archdiocese of Chieti) |
| 1853.12.17 | Archdiocese of Lucca lost territory to Diocese of Massa Carrara |
| 1854 | Diocese of Brugnato lost territory to Diocese of Massa Carrara |
| 1854 | Diocese of Luni–Sarzana lost territory to Diocese of Massa Carrara |
| 1854.11.30 | Diocese of Sant’Agata de’ Goti lost territory to Diocese of Acerra |
| 1855 | Diocese of Luni–Sarzana lost territory to Diocese of Pontremoli |
| 1855.05.29 | Abbacy nullius of San Pietro di Novalesa was suppressed (to Diocese of Susa) |
| 1855.06.25 | Diocese of Foggia was established (from Metropolitan Archdiocese of Manfredonia and Diocese of Troia and without ecclesiastical province) |
| 1855.08.01 | Diocese of Brugnato lost territory to Diocese of Pontremoli |
| 1855.08.22 | Diocese of Modena was promoted as Metropolitan Archdiocese of Modena (with suffragan sees Borgo San Donnino, Carpi, Guastalla, Massa Carrara and Reggio Emilia) |
| 1859.07 | Archdiocese of Spoleto lost territory to Diocese of Rieti |
| 1859.09.04 | Diocese of Catania was promoted as Archdiocese of Catania (without ecclesiastical province) |
| 1860.04.21 | Archdiocese of Barletta was restored (from Metropolitan Archdiocese of Trani and became suffragan of Trani) |
| 1860.06.14 | Diocese of Ventimiglia lost territory to Diocese of Cuneo |
| 1866 | Diocese of Reggio Emilia lost territory to Diocese of Guastalla |
| 1866 | Abbacy nullius of Santissimo Salvatore (Italo-Albanese Rite) was suppressed (to Metropolitan Archdiocese of Messina) |
| 1870.08.29 | Diocese of Como lost territory to Diocese of Chur |
| 1871 | Abbacy nullius of San Giovanni in Venere was suppressed (to Metropolitan Archdiocese of Chieti) |
| 1872 | Diocese of Mantova lost territory to Diocese of Carpi |
| 1872 | Diocese of Corneto was renamed as Diocese of Tarquinia |
| 1872.06.03 | Diocese of Acireale was established (from Metropolitan Archdiocese of Messina and Archdiocese of Catania and without ecclesiastical province) |
| 1874.08.01 | Diocese of Asti lost territory to Diocese of Casale Monferrato |
| 1874.08.01 | Metropolitan Archdiocese of Vercelli lost territory to Diocese of Casale Monferrato |
| 1876.01.19 | Diocese of L’Aquila was promoted as Archdiocese of L’Aquila |
| 1878 | Provostry nullius of Atina was restored (from Territorial Abbacy of Montecassino) |
| 1882.03.27 | Diocese of Perugia was promoted as Archdiocese of Perugia (without ecclesiastical province) |
| 1883.08.31 | Territorial Abbacy of Santissimo Salvatore (Italo-Albanese Rite) was restored |
| 1885 | Titular Episcopal See of Sinita was renamed as Titular Episcopal See of Sinis |
| 1886 | Diocese of Cuneo lost territory to Diocese of Ventimiglia |
| 1886 | Diocese of Ventimiglia lost territory to Diocese of Nice |
| 1892.08.14 | Abbacy nullius of Fontevivo was suppressed (to Diocese of Parma and united to Diocese of Parma) |
| 1892.12.03 | Diocese of Chiavari was established (from Metropolitan Archdiocese of Genova and became suffragan of Genova) |
| 1898 | Diocese of Cassano all’Jonio lost territory to Diocese of Policastro |
| 1898 | Diocese of Montepeloso was renamed as Diocese of Irsina |
| 1904.09.14 | Diocese of Ancona e Umana was promoted as Archdiocese of Ancona e Umana (without ecclesiastical province) |
| 1908.03.25 | Diocese of Modigliana lost territory to Diocese of Sarsina |
| 1910.08.05 | Abbacy nullius of San Michele Arcangelo di Montescaglioso was suppressed (to Metropolitan Archdiocese of Acerenza and united to Metropolitan Archdiocese of Acerenza) |
| 1911 | Diocese of Tuscanella was renamed as Diocese of Tuscania |
| 1914.03.04 | Diocese of Ariano lost territory to Diocese of Lucera |
| 1914.05.05 | Diocese of Ostia–Velletri was renamed as Diocese of Ostia (lost territory to establish Diocese of Velletri) |
| 1914.05.05 | Diocese of Velletri was restored (from Diocese of Ostia–Velletri and became suffragan of Roma) |
| 1915.01.02 | Diocese of Nocera Umbra was renamed as Diocese of Nocera Umbra–Gualdo Tadino |
| 1915.02.12 | Diocese of Bisarcio was suppressed (to establish Diocese of Ozieri) |
| 1915.02.12 | Diocese of Ozieri was established (from the suppressed Diocese of Bisarcio and became suffragan of Sassari) |
| 1916 | Metropolitan Archdiocese of Benevento lost territory to Diocese of Lucera |
| 1916 | Diocese of Larino lost territory to Diocese of San Severo |
| 1916.09 | Metropolitan Archdiocese of Firenze lost territory to Diocese of Prato |
| 1916.09 | Diocese of Pistoia lost territory to Diocese of Prato |
| 1919 | Diocese of Chioggia lost territory to Patriarchal See of Venezia |
| 1919.02.13 | Diocese of Bisignano lost territory to Diocese of Lungro |
| 1919.02.13 | Diocese of Cassano all’Jonio lost territory to Diocese of Lungro |
| 1919.02.13 | Archdiocese of Cosenza lost territory to Diocese of Lungro |
| 1919.02.13 | Ordinariate of Italia continentale (Italo-Albanese Rite) was promoted as Diocese of Lungro (gained territory from Archdiocese of Cosenza, Archdiocese of Rossano, Diocese of Bisignano, Diocese of Cassano all’Jonio and Diocese of San Marco and without ecclesiastical province) |
| 1919.02.13 | Archdiocese of Rossano lost territory to Diocese of Lungro |
| 1919.02.13 | Diocese of San Marco lost territory to Diocese of Lungro |
| 1920.04.08 | Abbacy nullius of Santa Maria di Polsi was suppressed (to Diocese of Gerace and united to Diocese of Gerace) |
| 1921.03.21 | Archdiocese of Gaeta lost territory to Diocese of Veroli |
| 1921.09.30 | Metropolitan Archdiocese of Conza lost territory to Diocese of Campagna |
| 1923.08.04 | Diocese of Bobbio was renamed as Diocese of Bobbio–San Colombano (gained territory from the suppressed Abbacy nullius of San Colombano) |
| 1923.08.04 | Abbacy nullius of San Colombano was suppressed (to Diocese of Bobbio–San Colombano) |
| 1923.11.13 | Metropolitan Archdiocese of Udine lost territory to Diocese of Concordia |
| 1925.03.06 | Military Vicariate of Italy was established |
| 1925.04.25 | Diocese of Trieste lost territory to Diocese of Rijeka–Opatija |
| 1925.06.03 | Diocese of Poggio Mirteto was suppressed (to Diocese of Rieti and Diocese of Sabina e Poggio Mirteto) |
| 1925.06.03 | Diocese of Sabina was renamed as Diocese of Sabina e Poggio Mirteto (gained territory from the suppressed Diocese of Poggio Mirteto) |
| 1926 | Titular Episcopal See of Sinis was suppressed |
| 1926.03.20 | Territorial Prelature of Beatissima Vergine Maria del Santissimo Rosario was established (from Diocese of Castellammare di Stabia and Diocese of Nola and became suffragan of Napoli) |
| 1926.04.16 | Metropolitan Archdiocese of Udine lost territory to Diocese of Ceneda |
| 1927.02.14 | Diocese of Treviso lost territory to Patriarchal See of Venezia |
| 1927.06.05 | Diocese of Catanzaro was promoted as Archdiocese of Catanzaro |
| 1927.06.29 | Diocese of Boiano was renamed as Diocese of Boiano–Campobasso |
| 1927.09.22 | Diocese of Borgo San Donnino was renamed as Diocese of Fidenza |
| 1928.01.27 | Diocese of Galtellì–Nuoro was suppressed (to establish Diocese of Nuoro) |
| 1928.01.27 | Diocese of Nuoro was established (from the suppressed Diocese of Galtellì–Nuoro and became suffragan of Cagliari) |
| 1929.01.12 | Diocese of La Spezia was established (from Diocese of Luni–Sarzana and became suffragan of Genova) |
| 1929.06.14 | Diocese of Trento was promoted as Archdiocese of Trento |
| 1934 | Diocese of Trieste lost territory to Diocese of Rijeka–Opatija |
| 1934.09.15 | Diocese of Loreto was suppressed (to Diocese of Recanati–Loreto) |
| 1934.09.15 | Diocese of Recanati was renamed as Diocese of Recanati–Loreto (gained territory from the suppressed Diocese of Loreto) |
| 1935.05.08 | Diocese of Castellammare di Stabia lost territory to Territorial Prelature of Beatissima Vergine Maria del Santissimo Rosario |
| 1935.05.08 | Diocese of Nola lost territory to Territorial Prelature of Beatissima Vergine Maria del Santissimo Rosario |
| 1935.10.11 | Apostolic Administration of Loreto was restored (from Diocese of Recanati–Loreto) |
| 1935.10.11 | Diocese of Recanati–Loreto was renamed as Diocese of Recanati (lost territory to establish Apostolic Administration of Loreto) |
| 1937.06.05 | Diocese of Nocera Umbra–Gualdo Tadino lost territory to Diocese of Foligno |
| 1937.09.26 | Territorial Abbacy of Santa Maria di Grottaferrata (Italo-Albanese Rite) was established |
| 1937.10.26 | Metropolitan Archdiocese of Monreale lost territory to Diocese of Piana dei Greci |
| 1937.10.26 | Metropolitan Archdiocese of Palermo lost territory to Diocese of Piana dei Greci |
| 1937.10.26 | Ordinariate of Silicia (Italo-Albanese Rite) was promoted as Diocese of Piana dei Greci (gained territory from Metropolitan Archdiocese of Monreale and Metropolitan Archdiocese of Palermo and without ecclesiastical province) |
| 1938 | Diocese of Larino lost territory to Metropolitan Archdiocese of Manfredonia |
| 1938.12.31 | Diocese of Alghero lost territory to Diocese of Nuoro |
| 1939.05.13 | Diocese of Ceneda was renamed as Diocese of Vittorio Veneto |
| 1939.07.20 | Diocese of Massa Carrara was renamed as Diocese of Apuania |
| 1941.10.25 | Diocese of Piana dei Greci (Italo-Albanese Rite) was renamed as Diocese of Piana degli Albanesi |
| 1942.06.30 | Territorial Abbacy of San Paolo fuori le Mura lost territory to Diocese of Amelia |
| 1943 | Diocese of Padova lost territory to Diocese of Feltre |
| 1945.08.11 | Metropolitan Archdiocese of Acerenza lost territory to Archdiocese of Matera |
| 1945.11.24 | Diocese of Capaccio–Vallo was renamed as Diocese of Vallo di Lucania |
| 1946.01.05 | Diocese of Porto e Santa Rufina lost territory to Papal See of Roma |
| 1947 | Metropolitan Archdiocese of Torino lost territory to Diocese of Gap and Diocese of Saint-Jean-de-Maurienne |
| 1947 | Diocese of Ventimiglia lost territory to Diocese of Nice |
| 1947.02.22 | Diocese of Cervia lost territory to Diocese of Comacchio |
| 1947.05.10 | Diocese of Arezzo lost territory to Territorial Abbacy of Monte Oliveto Maggiore |
| 1947.05.10 | Diocese of Pienza lost territory to Territorial Abbacy of Monte Oliveto Maggiore |
| 1948.04.24 | Diocese of Fidenza exchanged territory with Diocese of Parma |
| 1948.04.24 | Diocese of Parma exchanged territory with Diocese of Fidenza |
| 1948.05.22 | Diocese of Ostia lost territory to Papal See of Roma |
| 1949.05.14 | Diocese of Tricarico lost territory to Diocese of Anglona–Tursi |
| 1949.07.01 | Metropolitan Archdiocese of Chieti lost territory to Diocese of Penne e Pescara |
| 1949.07.01 | Diocese of Penne was renamed as Diocese of Penne e Pescara (gained territory from Metropolitan Archdiocese of Chieti and lost territory to Diocese of Teramo) |
| 1950.01.19 | Diocese of Cuneo exchanged territory with Diocese of Mondovì |
| 1950.01.19 | Diocese of Mondovì exchanged territory with Diocese of Cuneo |
| 1950.01.24 | Diocese of Penne e Pescara lost territory to Diocese of Teramo |
| 1950.03.19 | Diocese of Terracina exchanged territory with Diocese of Velletri |
| 1950.03.19 | Diocese of Velletri exchanged territory with Diocese of Terracina |
| 1950.07.11 | Diocese of Noto lost territory to Metropolitan Archdiocese of Siracusa |
| 1950.07.11 | Diocese of Ragusa was established (from Metropolitan Archdiocese of Siracusa and Diocese of Noto and became suffragan of Siracusa) |
| 1950.09.15 | Diocese of Mazara del Vallo exchanged territory with Diocese of Trapani |
| 1950.09.15 | Diocese of Trapani exchanged territory with Diocese of Mazara del Vallo |
| 1951.05.08 | Territorial Prelature of Beatissima Vergine Maria del Santissimo Rosario was renamed as Territorial Prelature of Pompei |
| 1952.01.06 | Metropolitan Archdiocese of Santa Severina was demoted as Archdiocese of Santa Severina (without ecclesiastical province) |
| 1954.02.22 | Diocese of Gerace was renamed as Diocese of Gerace–Locri |
| 1954.04.05 | Diocese of Porto e Santa Rufina lost territory to Papal See of Roma |
| 1954.07.02 | Archdiocese of Matera was promoted as Metropolitan Archdiocese of Matera (with suffragan sees Anglona–Tursi and Tricarico and gained title of San Michele Arcangelo di Montescaglioso) |
| 1954.07.27 | Diocese of Volterra lost territory to Metropolitan Archdiocese of Siena |
| 1954.11.16 | Diocese of Noto lost territory to Diocese of Ragusa |
| 1955 | Metropolitan Archdiocese of Pisa lost territory to Archdiocese of Lucca |
| 1955 | Diocese of Pontremoli lost territory to Diocese of Luni–Sarzana |
| 1956.02.29 | Diocese of Veroli was renamed as Diocese of Veroli–Frosinone |
| 1956.04.24 | Diocese of Ortona lost territory to Metropolitan Archdiocese of Lanciano |
| 1957 | Diocese of Priverno lost territory to Diocese of Terracina |
| 1957.07.09 | Diocese of Aversa exchanged territory with Diocese of Pozzuoli |
| 1957.07.09 | Diocese of Pozzuoli exchanged territory with Diocese of Aversa |
| 1959.07.18 | Diocese of Bova lost territory to Diocese of Gerace–Locri |
| 1959.07.26 | Diocese of Apuania lost territory to Diocese of Brugnato and Diocese of Luni–Sarzana |
| 1959.07.26 | Diocese of Brugnato exchanged territory with Diocese of Chiavari |
| 1959.07.26 | Diocese of Chiavari lost territory to Diocese of Luni–Sarzana |
| 1959.08.01 | Diocese of Ugento was renamed as Diocese of Ugento–Santa Maria di Leuca |
| 1960.07.08 | Metropolitan Archdiocese of Palermo lost territory to Diocese of Piana degli Albanesi |
| 1962.02.19 | Diocese of Città di Castello lost territory to Diocese of Arezzo |
| 1963.12.16 | Diocese of Nicotera lost territory to Archdiocese of Cosenza |
| 1963.12.31 | Diocese of Tropea lost territory to Archdiocese of Cosenza and Diocese of Nicastro |
| 1964.07.06 | Diocese of Brixen was renamed as Diocese of Bolzano–Bressanone (gained territory from Archdiocese of Trento and lost territory to Diocese of Belluno) |
| 1964.07.06 | Archdiocese of Trento was promoted as Metropolitan Archdiocese of Trento (lost territory to Diocese of Bolzano–Bressanone) |
| 1965.02.02 | Diocese of Mondovì lost territory to Diocese of Albenga |
| 1965.02.08 | Papal See of Roma lost territory to Diocese of Porto e Santa Rufina |
| 1965.06.24 | Apostolic Administration of Loreto was promoted as Territorial Prelature of Loreto (gained territory from Diocese of Recanati) |
| 1965.06.24 | Diocese of Recanati lost territory to Territorial Prelature of Loreto |
| 1965.10.25 | Diocese of Ascoli Piceno lost territory to Diocese of Rieti |
| 1965.11.17 | Diocese of Ascoli Piceno exchanged territory with Diocese of Teramo |
| 1965.11.17 | Diocese of Teramo exchanged territory with Diocese of Ascoli Piceno |
| 1966 | Titular Episcopal See of Amiterno was restored |
| 1966 | Titular Episcopal See of Arpi was established |
| 1966 | Titular Episcopal See of Blanda was restored |
| 1966 | Titular Episcopal See of Canne was restored |
| 1966 | Titular Episcopal See of Capo della Foresta was restored |
| 1966 | Titular Episcopal See of Claterna was restored |
| 1966 | Titular Episcopal See of Eclena was restored |
| 1966 | Titular Episcopal See of Equilio was restored |
| 1966 | Titular Episcopal See of Eraclea was restored |
| 1966 | Titular Episcopal See of Faleri was restored |
| 1966 | Titular Episcopal See of Fidene was restored |
| 1966 | Titular Episcopal See of Forconio was restored |
| 1966 | Titular Episcopal See of Foro Flaminii was restored |
| 1966 | Titular Episcopal See of Gabi was restored |
| 1966 | Titular Episcopal See of Lilibeo was restored |
| 1966 | Titular Episcopal See of Malamocco was restored |
| 1966 | Titular Episcopal See of Martana was established |
| 1966 | Titular Episcopal See of Monterano was restored |
| 1966 | Titular Episcopal See of Nomento was restored |
| 1966 | Titular Episcopal See of Pausula was established |
| 1966 | Titular Episcopal See of Pesto was restored |
| 1966 | Titular Episcopal See of Plestia was restored |
| 1966 | Titular Episcopal See of Roselle was restored |
| 1966 | Titular Episcopal See of Sabiana was restored |
| 1966 | Titular Episcopal See of Salpi was restored |
| 1966 | Titular Episcopal See of Subaugusta was restored |
| 1966 | Titular Episcopal See of Sulci was restored |
| 1966 | Titular Episcopal See of Treba was restored |
| 1966 | Titular Episcopal See of Tricala was restored |
| 1966 | Titular Episcopal See of Tronto was restored |
| 1966 | Titular Episcopal See of Velia was established |
| 1966 | Titular Episcopal See of Voghenza was restored |
| 1966 | Titular Episcopal See of Volturno was established |
| 1967 | Titular Episcopal See of Eclena was renamed as Titular Episcopal See of Eclano |
| 1967 | Titular Episcopal See of Sabiana was renamed as Titular Episcopal See of Sabiona |
| 1967 | Titular Episcopal See of Zuglio was restored |
| 1967.09.12 | Diocese of Terracina was renamed as Diocese of Terracina–Latina (gained territory from Diocese of Velletri) |
| 1967.09.12 | Diocese of Velletri lost territory to Diocese of Terracina–Latina |
| 1968 | Titular Episcopal See of Agropoli was restored |
| 1968 | Titular Episcopal See of Alessano was restored |
| 1968 | Titular Episcopal See of Altino was restored |
| 1968 | Titular Episcopal See of Anzio was restored |
| 1968 | Titular Episcopal See of Aquaviva was restored |
| 1968 | Titular Metropolitan See of Aquileia was established (from former Patriarchal See of Aquileia) |
| 1968 | Titular Episcopal See of Asolo was restored |
| 1968 | Titular Episcopal See of Atella was restored |
| 1968 | Titular Episcopal See of Belcastro was restored |
| 1968 | Titular Episcopal See of Bettona was restored |
| 1968 | Titular Episcopal See of Bevagna was restored |
| 1968 | Titular Episcopal See of Bitetto was restored |
| 1968 | Titular Episcopal See of Brescello was restored |
| 1968 | Titular Episcopal See of Campli was restored |
| 1968 | Titular Episcopal See of Caorle was restored |
| 1968 | Titular Episcopal See of Capri was restored |
| 1968 | Titular Episcopal See of Carini was restored |
| 1968 | Titular Episcopal See of Carinola was restored |
| 1968 | Titular Episcopal See of Castro was restored |
| 1968 | Titular Episcopal See of Castro was restored |
| 1968 | Titular Episcopal See of Castro was restored |
| 1968 | Titular Episcopal See of Cerenzia was restored |
| 1968 | Titular Episcopal See of Cerveteri was restored |
| 1968 | Titular Episcopal See of Città Ducale was restored |
| 1968 | Titular Episcopal See of Civitate was restored |
| 1968 | Titular Episcopal See of Dolia was restored |
| 1968 | Titular Episcopal See of Dragonara was restored |
| 1968 | Titular Episcopal See of Fiorentino was restored |
| 1968 | Titular Episcopal See of Fondi was restored |
| 1968 | Titular Episcopal See of Forlimpopoli was restored (from Diocese of Bertinoro) |
| 1968 | Titular Episcopal See of Formia was restored |
| 1968 | Titular Episcopal See of Forum Traiani was restored |
| 1968 | Titular Metropolitan See of Grado was established (from former Patriarchal See of Grado) |
| 1968 | Titular Episcopal See of Guardialfiera was restored |
| 1968 | Titular Episcopal See of Isola was restored |
| 1968 | Titular Episcopal See of Labico was restored |
| 1968 | Titular Episcopal See of Lavello was restored |
| 1968 | Titular Episcopal See of Lentini was restored |
| 1968 | Titular Episcopal See of Lesina was restored |
| 1968 | Titular Episcopal See of Lettere was restored |
| 1968 | Titular Episcopal See of Malamocco was suppressed |
| 1968 | Titular Episcopal See of Martirano was restored |
| 1968 | Titular Episcopal See of Massa Lubrense was restored |
| 1968 | Titular Episcopal See of Minervino Murge was restored |
| 1968 | Titular Episcopal See of Minori was restored |
| 1968 | Titular Episcopal See of Minturno was restored |
| 1968 | Titular Episcopal See of Montecorvino was restored |
| 1968 | Titular Episcopal See of Montemarano was restored |
| 1968 | Titular Episcopal See of Monteverde was restored |
| 1968 | Titular Episcopal See of Mottola was restored |
| 1968 | Titular Episcopal See of Oderzo was restored |
| 1968 | Titular Episcopal See of Otricoli was restored |
| 1968 | Titular Episcopal See of Passo Corese was restored |
| 1968 | Titular Episcopal See of Ploaghe was restored |
| 1968 | Titular Episcopal See of Polignano was restored |
| 1968 | Titular Episcopal See of Potenza Picena was restored |
| 1968 | Titular Episcopal See of Ravello was restored |
| 1968 | Titular Episcopal See of Sala Consilina was restored |
| 1968 | Titular Episcopal See of San Leone was restored |
| 1968 | Titular Episcopal See of Santa Giusta was restored |
| 1968 | Titular Episcopal See of Satriano was restored |
| 1968 | Titular Episcopal See of Scala was restored |
| 1968 | Titular Episcopal See of Sorres was restored |
| 1968 | Titular Episcopal See of Spello was restored |
| 1968 | Titular Episcopal See of Suelli was restored |
| 1968 | Titular Episcopal See of Tauriano was restored |
| 1968 | Titular Episcopal See of Termini Imerese was restored |
| 1968 | Titular Episcopal See of Tindari was restored |
| 1968 | Titular Episcopal See of Torcello was restored |
| 1968 | Titular Episcopal See of Tortiboli was restored |
| 1968 | Titular Episcopal See of Trevi was restored |
| 1968 | Titular Episcopal See of Trevico was restored |
| 1968 | Titular Episcopal See of Troina was restored |
| 1968 | Titular Episcopal See of Urbisaglia was restored |
| 1968 | Titular Episcopal See of Vescovìo was restored |
| 1968 | Titular Episcopal See of Vibo Valentia was restored |
| 1968 | Titular Episcopal See of Vico Equense was restored |
| 1968 | Titular Episcopal See of Vulturara was restored |
| 1969 | Titular Episcopal See of Bomarzo was restored |
| 1969 | Titular Episcopal See of Castello was restored |
| 1969 | Titular Episcopal See of Falerone was restored |
| 1969 | Titular Episcopal See of Strongoli was restored |
| 1969 | Titular Episcopal See of Taormina was restored |
| 1969 | Titular Episcopal See of Umbriatico was restored |
| 1970 | Titular Episcopal See of Blera was restored |
| 1970 | Titular Episcopal See of Bolsena was restored |
| 1970 | Titular Episcopal See of Buxentum was established |
| 1970 | Titular Episcopal See of Caudium was restored |
| 1970 | Titular Episcopal See of Civitanova was established |
| 1970 | Titular Episcopal See of Cuma was restored |
| 1970 | Titular Episcopal See of Ferento was restored |
| 1970 | Titular Episcopal See of Frigento was restored |
| 1970 | Titular Episcopal See of Galazia in Campania was restored |
| 1970 | Titular Episcopal See of Grumentum was restored |
| 1970 | Titular Episcopal See of Lorium was restored |
| 1970 | Titular Episcopal See of Miseno was restored |
| 1970 | Titular Episcopal See of Ofena was restored |
| 1970 | Titular Episcopal See of Tharros was restored |
| 1970 | Titular Episcopal See of Tre Taverne was restored |
| 1970 | Titular Episcopal See of Trevi nel Lazio was established |
| 1971 | Titular Episcopal See of Pesto was renamed as Titular Episcopal See of Pesto |
| 1971.01.12 | Diocese of Concordia was renamed as Diocese of Concordia–Pordenone |
| 1972 | Diocese of Larino lost territory to Diocese of San Severo |
| 1972.08.15 | Archdiocese of Ancona e Umana was promoted as Metropolitan Archdiocese of Ancona e Umana (with suffragan sees Jesi and Osimo) |
| 1972.08.15 | Archdiocese of L’Aquila was promoted as Metropolitan Archdiocese of L’Aquila (with suffragan sees Marsi and Sulmona) |
| 1972.08.15 | Archdiocese of Perugia was promoted as Metropolitan Archdiocese of Perugia (with suffragan sees Assisi, Città della Pieve, Città di Castello, Foligno, Gubbio and Nocera Umbra–Gualdo Tadino) |
| 1972.09.25 | Diocese of Cava was renamed as Diocese of Cava de’ Tirreni |
| 1973 | Diocese of Città della Pieve lost territory to Diocese of Acquapendente and Diocese of Chiusi |
| 1973 | Diocese of Civita Castellana lost territory to Diocese of Bagnoregio |
| 1973.01.05 | Diocese of Anglona–Tursi exchanged territory with Diocese of Cassano all’Jonio |
| 1973.01.05 | Diocese of Cassano all’Jonio exchanged territory with Diocese of Anglona–Tursi |
| 1973.02.11 | Diocese of Boiano–Campobasso was promoted as Archdiocese of Boiano–Campobasso (without ecclesiastical province) |
| 1973.02.11 | Diocese of Potenza was promoted as Archdiocese of Potenza (without ecclesiastical province) |
| 1973.03.24 | Diocese of Bagnoregio lost territory to Diocese of Orvieto |
| 1973.03.24 | Diocese of Orvieto lost territory to Diocese of Acquapendente |
| 1973.03.31 | Diocese of Campagna lost territory to Archdiocese of Potenza |
| 1973.03.31 | Diocese of Muro Lucano lost territory to Diocese of Campagna |
| 1973.11.21 | Diocese of Nicastro lost territory to Archdiocese of Cosenza |
| 1973.11.22 | Archdiocese of Cosenza lost territory to Diocese of Lungro |
| 1973.12.01 | Diocese of Albenga was renamed as Diocese of Albenga–Imperia |
| 1974 | Titular Episcopal See of Buxentum was suppressed |
| 1974 | Titular Episcopal See of Eca was restored |
| 1974.10.18 | Metropolitan Archdiocese of Udine lost territory to Diocese of Concordia–Pordenone |
| 1975 | Titular Episcopal See of Forum Traiani was renamed as Titular Episcopal See of Fordongianus |
| 1975 | Titular Episcopal See of Numana was restored |
| 1975.07.03 | Diocese of Ventimiglia was renamed as Diocese of Ventimiglia–San Remo |
| 1975.07.05 | Metropolitan Archdiocese of Ancona e Umana was renamed as Metropolitan Archdiocese of Ancona |
| 1975.08.04 | Diocese of Luni–Sarzana was suppressed (to Diocese of La Spezia and to establish Diocese of Sarzana) |
| 1975.08.04 | Diocese of Sarzana was established (from the suppressed Diocese of Luni–Sarzana) |
| 1975.10.07 | Diocese of Arezzo lost territory to Metropolitan Archdiocese of Siena |
| 1975.10.07 | Diocese of Pistoia lost territory to Diocese of Prato |
| 1975.10.07 | Diocese of Sansepolcro lost territory to Diocese of Cesena and Diocese of Forlì |
| 1975.10.07 | Diocese of Sovana–Pitigliano lost territory to Diocese of Grosseto |
| 1976 | Titular Episcopal See of Castro was renamed as Titular Episcopal See of Castro di Puglia |
| 1976 | Titular Episcopal See of Castro was renamed as Titular Episcopal See of Castro di Sardegna |
| 1976.06.21 | Metropolitan Archdiocese of L’Aquila exchanged territory with Diocese of Rieti |
| 1976.06.21 | Diocese of Narni lost territory to Diocese of Rieti |
| 1976.06.21 | Diocese of Norcia lost territory to Diocese of Rieti |
| 1976.06.21 | Diocese of Rieti exchanged territory with Metropolitan Archdiocese of L’Aquila |
| 1976.06.21 | Archdiocese of Spoleto lost territory to Diocese of Rieti |
| 1976.08.21 | Metropolitan Archdiocese of Acerenza was demoted as Diocese of Acerenza (became suffragan of Potenza) |
| 1976.08.21 | Diocese of Andria lost territory to Diocese of Venosa |
| 1976.08.21 | Archdiocese of Boiano–Campobasso was promoted as Metropolitan Archdiocese of Boiano–Campobasso (with suffragan sees Isernia, Termoli, Trivento and Venafro) |
| 1976.08.21 | Metropolitan Archdiocese of Matera was demoted as Diocese of Matera (lost territory to Diocese of Castellaneta and became suffragan of Potenza) |
| 1976.08.21 | Archdiocese of Potenza was promoted as Metropolitan Archdiocese of Potenza (with suffragan sees Acerenza, Anglona–Tursi, Marsico Nuovo, Matera, Melfi, Muro Lucano, Rapolla, Tricarico and Venosa) |
| 1976.08.21 | Diocese of Venosa lost territory to Diocese of Gravina |
| 1976.09.08 | Diocese of Acerenza lost territory to Metropolitan Archdiocese of Potenza |
| 1976.09.08 | Diocese of Anglona–Tursi was suppressed (to Diocese of Cassano all’Jonio and to establish Diocese of Tursi–Lagonegro) |
| 1976.09.08 | Metropolitan Archdiocese of Conza lost territory to Diocese of Melfi |
| 1976.09.08 | Diocese of Matera lost territory to Diocese of Castellaneta |
| 1976.09.08 | Diocese of Muro Lucano lost territory to Diocese of Melfi |
| 1976.09.08 | Diocese of Rapolla lost territory to Metropolitan Archdiocese of Potenza |
| 1976.09.08 | Territorial Abbacy of Santissima Trinità di Cava de’ Tirreni lost territory to Metropolitan Archdiocese of Potenza |
| 1976.09.08 | Diocese of Tricarico lost territory to Diocese of Matera |
| 1976.09.08 | Diocese of Tursi–Lagonegro was restored (from Metropolitan Archdiocese of Potenza, Diocese of Cassano all’Jonio, Diocese of Diano–Teggiano, Diocese of Matera and Diocese of Policastro, from the suppressed Diocese of Anglona–Tursi and became suffragan of Potenza) |
| 1976.12.08 | Metropolitan Archdiocese of Ferrara was demoted as Archdiocese of Ferrara (became suffragan of Bologna) |
| 1977.01.01 | Metropolitan Archdiocese of Genova lost territory to Diocese of Livorno |
| 1977.02.22 | Diocese of Rimini exchanged territory with Diocese of Montefeltro |
| 1977.02.22 | Diocese of Montefeltro was renamed as Diocese of San Marino–Montefeltro (lost territory to Diocese of Sarsina, exchanged territory with Diocese of Rimini and became suffragan of Ravenna) |
| 1977.03.21 | Provostry nullius of Atina was suppressed (to Territorial Abbacy of Montecassino) |
| 1977.03.21 | Territorial Abbacy of Montecassino lost territory to Metropolitan Archdiocese of Chieti, Diocese of Aquino, Diocese of Isernia, Diocese of Penne e Pescara, Diocese of Sessa Aurunca, Diocese of Sulmona, Diocese of Teano, Diocese of Trivento, Diocese of Valva and Diocese of Venafro |
| 1977.10.17 | Metropolitan Archdiocese of Gorizia e Gradisca lost territory to Diocese of Koper |
| 1977.10.17 | Diocese of Trieste was renamed as Diocese of Trieste (lost territory to Diocese of Poreč i Pula and exchanged territory with Diocese of Koper) |
| 1977.10.17 | Diocese of Trivento lost territory to Diocese of Sulmona |
| 1977.10.28 | Diocese of Città della Pieve lost territory to Diocese of Sovana–Pitigliano |
| 1977.10.28 | Diocese of Montalcino lost territory to Diocese of Pienza |
| 1977.10.28 | Diocese of Pienza lost territory to Territorial Abbacy of Monte Oliveto Maggiore |
| 1977.10.28 | Metropolitan Archdiocese of Siena lost territory to Diocese of Montalcino |
| 1977.11.15 | Diocese of Ariano exchanged territory with Diocese of Bovino |
| 1977.11.15 | Diocese of Bovino exchanged territory with Diocese of Ariano |
| 1977.11.28 | Diocese of Acerenza was promoted as Archdiocese of Acerenza |
| 1977.12.03 | Diocese of Matera was promoted as Archdiocese of Matera (lost territory to Diocese of Castellaneta) |
| 1978 | Diocese of Ascoli Satriano exchanged territory with Diocese of Bovino |
| 1978 | Diocese of Bovino exchanged territory with Diocese of Ascoli Satriano |
| 1978 | Archdiocese of Cosenza lost territory to Diocese of Lungro |
| 1978.05.14 | Diocese of Massa Marittima e Populonia was renamed as Diocese of Massa Marittima–Piombino |
| 1978.05.14 | Titular Episcopal See of Populonia was restored |
| 1978.05.23 | Metropolitan Archdiocese of Milano (Ambrosian Rite) lost territory to Diocese of Lodi |
| 1978.11.21 | Diocese of Arezzo lost territory to Metropolitan Archdiocese of Siena |
| 1979.01.15 | Metropolitan Archdiocese of Milano (Ambrosian Rite) lost territory to Diocese of Pavia |
| 1979.01.21 | Diocese of Lodi exchanged territory with Diocese of Pavia |
| 1979.01.21 | Diocese of Pavia exchanged territory with Diocese of Lodi |
| 1979.04.04 | Diocese of Cariati lost territory to Diocese of Crotone |
| 1979.04.04 | Diocese of Cassano all’Jonio lost territory to Diocese of San Marco Argentano–Scalea |
| 1979.04.04 | Diocese of Crotone lost territory to Archdiocese of Santa Severina |
| 1979.04.04 | Diocese of San Marco was renamed as Diocese of San Marco Argentano–Scalea (gained territory from Diocese of Cassano all’Jonio and lost territory to Archdiocese of Cosenza) |
| 1979.04.30 | Metropolitan Archdiocese of Capua was demoted as Archdiocese of Capua (became suffragan of Napoli) |
| 1979.04.30 | Metropolitan Archdiocese of Conza was demoted as Archdiocese of Conza (became suffragan of Benevento) |
| 1979.04.30 | Diocese of Foggia was promoted as Metropolitan Archdiocese of Foggia (with suffragan sees Manfredonia, Ascoli Satriano, Cerignola, Lucera, San Severo, Troia and Vieste) |
| 1979.04.30 | Metropolitan Archdiocese of Manfredonia was demoted as Archdiocese of Manfredonia (became suffragan of Foggia) |
| 1979.04.30 | Metropolitan Archdiocese of Sorrento was demoted as Archdiocese of Sorrento (became suffragan of Napoli) |
| 1979.06.10 | Diocese of Mileto lost territory to Metropolitan Archdiocese of Reggio Calabria and Diocese of Oppido Mamertina–Palmi |
| 1979.06.10 | Diocese of Oppido Mamertina was renamed as Diocese of Oppido Mamertina–Palmi (gained territory from Diocese of Mileto) |
| 1979.10.15 | Diocese of Avellino exchanged territory with Territorial Abbacy of Montevergine |
| 1979.10.15 | Diocese of Cava de’ Tirreni lost territory to Territorial Abbacy of Santissima Trinità di Cava de’ Tirreni |
| 1979.10.15 | Territorial Abbacy of Montevergine exchanged territory with Diocese of Avellino |
| 1979.10.15 | Diocese of Nocera de’ Pagani exchanged territory with Territorial Abbacy of Santissima Trinità di Cava de’ Tirreni |
| 1979.10.15 | Metropolitan Archdiocese of Salerno lost territory to Diocese of Nocera de’ Pagani |
| 1979.10.15 | Territorial Abbacy of Santissima Trinità di Cava de’ Tirreni lost territory to Diocese of Diano–Teggiano and Diocese of Vallo di Lucania |
| 1980.01.20 | Diocese of Oppido Mamertina–Palmi lost territory to Metropolitan Archdiocese of Reggio Calabria |
| 1980.04.14 | Diocese of Assisi lost territory to Archdiocese of Spoleto |
| 1980.10.20 | Metropolitan Archdiocese of Brindisi was demoted as Archdiocese of Brindisi (became suffragan of Lecce) |
| 1980.10.20 | Diocese of Lecce was promoted as Metropolitan Archdiocese of Lecce (with suffragan sees Brindisi, Otranto, Gallipoli, Nardò, Ostuni and Ugento–Santa Maria di Leuca) |
| 1980.10.20 | Metropolitan Archdiocese of Otranto was demoted as Archdiocese of Otranto (became suffragan of Lecce) |
| 1980.10.20 | Metropolitan Archdiocese of Trani was demoted as Archdiocese of Trani (became suffragan of Bari e Canosa) |
| 1981 | Territorial Abbacy of San Paolo fuori le Mura lost territory to Papal See of Roma |
| 1981.03.25 | Abbacy nullius of Santi Vincenzo ed Anastasio alle Tre Fontane was suppressed (to Papal See of Roma, Diocese of Civita Castellana, Diocese of Nepi and Diocese of Sovana–Pitigliano–Orbetello) |
| 1981.03.25 | Diocese of Sovana–Pitigliano was renamed as Diocese of Sovana–Pitigliano–Orbetello (gained territory from the suppressed Abbacy nullius of Santi Vincenzo ed Anastasio alle Tre Fontane) |
| 1982 | Titular Episcopal See of Trevi nel Lazio was suppressed |
| 1982.02.27 | Metropolitan Archdiocese of Boiano–Campobasso was renamed as Metropolitan Archdiocese of Campobasso–Boiano |
| 1982.03.02 | Metropolitan Archdiocese of Lanciano was demoted as Archdiocese of Lanciano (became suffragan of Chieti) |
| 1982.03.02 | Diocese of Penne e Pescara was promoted as Metropolitan Archdiocese of Pescara–Penne (with suffragan sees Atri and Teramo) |
| 1982.11.28 | Personal Prelature of Opus Dei was established (from the suppressed Secular Institute of Opus Dei and depended on Sacred Congregation for Bishops) |
| 1983.01.21 | Metropolitan Archdiocese of Benevento exchanged territory with Metropolitan Archdiocese of Campobasso–Boiano |
| 1983.01.21 | Metropolitan Archdiocese of Campobasso–Boiano exchanged territory with Metropolitan Archdiocese of Benevento |
| 1983.01.21 | Diocese of Lucera lost territory to Metropolitan Archdiocese of Benevento |
| 1983.03.21 | Territorial Abbacy of San Paolo fuori le Mura lost territory to Diocese of Nepi |
| 1983.04.07 | Diocese of Ripatransone was renamed as Diocese of Ripatransone–San Benedetto del Tronto |
| 1983.05.25 | Diocese of Lacedonia lost territory to Diocese of Ascoli Satriano |
| 1984.03.19 | Archdiocese of Camerino lost territory to Diocese of Cingoli and Diocese of Fabriano |
| 1984.03.19 | Diocese of Città di Castello lost territory to Diocese of Cagli and Diocese of Cortona |
| 1984.03.19 | Diocese of Macerata exchanged territory with Diocese of Osimo |
| 1984.03.19 | Diocese of Nocera Umbra–Gualdo Tadino lost territory to Archdiocese of Camerino, Diocese of Fabriano, Diocese of Foligno, Diocese of Pergola and Diocese of Senigallia |
| 1984.03.19 | Diocese of Norcia lost territory to Archdiocese of Camerino |
| 1984.03.19 | Diocese of Osimo exchanged territory with Diocese of Macerata and Diocese of Recanati |
| 1984.03.19 | Diocese of Recanati exchanged territory with Diocese of Osimo |
| 1984.09.15 | Metropolitan Archdiocese of Modena lost territory to Diocese of Reggio Emilia |
| 1986.02.11 | Diocese of Gallese was suppressed (to Diocese of Civita Castellana) |
| 1986.02.11 | Diocese of Nepi was suppressed (to Diocese of Civita Castellana) |
| 1986.02.11 | Diocese of Orte was suppressed (to Diocese of Civita Castellana) |
| 1986.02.11 | Diocese of Sutri was suppressed (to Diocese of Civita Castellana) |
| 1986.03.27 | Diocese of Montefiascone was suppressed (to Diocese of Viterbo) |
| 1986.03.27 | Abbacy nullius of San Martino al Monte Cimino was suppressed (to Diocese of Viterbo and united to Diocese of Viterbo) |
| 1986.03.27 | Diocese of Tuscania was suppressed (to Diocese of Viterbo) |
| 1986.07.21 | Military Vicariate of Italy was promoted as Military Ordinariate of Ordinariato Militare per l’Italia |
| 1986.09.30 | Diocese of Acerno was suppressed (to Metropolitan Archdiocese of Salerno–Campagna–Acerno) |
| 1986.09.30 | Diocese of Acquapendente was suppressed (to Diocese of Viterbo, Acquapendente, Bagnoregio, Montefiascone, Tuscania e San Martino al Monte Cimino) |
| 1986.09.30 | Territorial Prelature of Acquaviva delle Fonti was suppressed (to Diocese of Altamura–Gravina–Acquaviva delle Fonti) |
| 1986.09.30 | Diocese of Adria was renamed as Diocese of Adria–Rovigo |
| 1986.09.30 | Diocese of Alatri was suppressed (to Diocese of Anagni–Alatri) |
| 1986.09.30 | Diocese of Ales was renamed as Diocese of Ales–Terralba (gained territory from the suppressed Diocese of Terralba) |
| 1986.09.30 | Diocese of Alghero was renamed as Diocese of Alghero–Bosa (gained territory from the suppressed Diocese of Bosa) |
| 1986.09.30 | Diocese of Alife was renamed as Diocese of Alife–Caiazzo (gained territory from the suppressed Diocese of Caiazzo) |
| 1986.09.30 | Territorial Prelature of Altamura was promoted as Diocese of Altamura–Gravina–Acquaviva delle Fonti (gained territory from Metropolitan Archdiocese of Bari e Canosa and gained territory from the suppressed Diocese of Gravina and Territorial Prelature of Acquaviva delle Fonti) |
| 1986.09.30 | Archdiocese of Amalfi was renamed as Archdiocese of Amalfi–Cava de’ Tirreni (gained territory from the suppressed Diocese of Cava de’ Tirreni) |
| 1986.09.30 | Diocese of Amelia was suppressed (to Diocese of Terni–Narni–Amelia) |
| 1986.09.30 | Diocese of Ampurias was suppressed (to establish Diocese of Tempio–Ampurias) |
| 1986.09.30 | Diocese of Anagni was renamed as Diocese of Anagni–Alatri (gained territory from the suppressed Diocese of Alatri) |
| 1986.09.30 | Metropolitan Archdiocese of Ancona was renamed as Metropolitan Archdiocese of Ancona–Osimo (gained territory from the suppressed Diocese of Osimo and lost suffragan see Osimo) |
| 1986.09.30 | Diocese of Aquino was suppressed (to Diocese of Sora–Aquino–Pontecorvo) |
| 1986.09.30 | Diocese of Arezzo was renamed as Diocese of Arezzo–Cortona–Sansepolcro (gained territory from Diocese of Montepulciano, gained territory from the suppressed Diocese of Cortona and Diocese of Sansepolcro and became suffragan of Firenze) |
| 1986.09.30 | Diocese of Ariano was renamed as Diocese of Ariano Irpino–Lacedonia (gained territory from the suppressed Diocese of Lacedonia) |
| 1986.09.30 | Diocese of Ascoli Satriano was suppressed (to Diocese of Cerignola–Ascoli Satriano) |
| 1986.09.30 | Diocese of Assisi was renamed as Diocese of Assisi–Nocera Umbra–Gualdo Tadino (gained territory from the suppressed Diocese of Nocera Umbra–Gualdo Tadino) |
| 1986.09.30 | Diocese of Atri was suppressed (to Diocese of Teramo–Atri) |
| 1986.09.30 | Diocese of Marsi was renamed as Diocese of Avezzano |
| 1986.09.30 | Diocese of Bagnoregio was suppressed (to Diocese of Viterbo, Acquapendente, Bagnoregio, Montefiascone, Tuscania e San Martino al Monte Cimino) |
| 1986.09.30 | Metropolitan Archdiocese of Bari e Canosa was renamed as Metropolitan Archdiocese of Bari–Bitonto (gained territory from the suppressed Diocese of Bitonto, lost territory to Diocese of Altamura–Gravina–Acquaviva delle Fonti and lost suffragan sees Barletta, Bisceglie, Bitonto, Giovinazzo, Monopoli, Ruvo and Terlizzi) |
| 1986.09.30 | Archdiocese of Barletta was suppressed (to Archdiocese of Trani–Barletta–Bisceglie) |
| 1986.09.30 | Diocese of Belluno was renamed as Diocese of Belluno–Feltre (gained territory from the suppressed Diocese of Feltre) |
| 1986.09.30 | Diocese of Bertinoro was suppressed (to Diocese of Forlì–Bertinoro) |
| 1986.09.30 | Diocese of Bisaccia was suppressed (to Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia) |
| 1986.09.30 | Diocese of Bisceglie was suppressed (to Archdiocese of Trani–Barletta–Bisceglie) |
| 1986.09.30 | Diocese of Bisignano was suppressed (to Archdiocese of Cosenza–Bisignano) |
| 1986.09.30 | Diocese of Bitonto was suppressed (to Metropolitan Archdiocese of Bari–Bitonto) |
| 1986.09.30 | Diocese of Bobbio–San Colombano was suppressed (to Metropolitan Archdiocese of Genova–Bobbio) |
| 1986.09.30 | Diocese of Bosa was suppressed (to Diocese of Alghero–Bosa) |
| 1986.09.30 | Diocese of Bova was suppressed (to Metropolitan Archdiocese of Reggio Calabria–Bova) |
| 1986.09.30 | Diocese of Bovino was suppressed (to Metropolitan Archdiocese of Foggia–Bovino) |
| 1986.09.30 | Archdiocese of Brindisi was renamed as Archdiocese of Brindisi–Ostuni (gained territory from the suppressed Diocese of Ostuni) |
| 1986.09.30 | Diocese of Brugnato was suppressed (to Diocese of La Spezia–Sarzana–Brugnato) |
| 1986.09.30 | Diocese of Cagli was suppressed (to Diocese of Fano–Fossombrone–Cagli–Pergola) |
| 1986.09.30 | Diocese of Caiazzo was suppressed (to Diocese of Alife–Caiazzo) |
| 1986.09.30 | Diocese of Calvi was suppressed (to Diocese of Teano–Calvi) |
| 1986.09.30 | Archdiocese of Camerino was renamed as Archdiocese of Camerino–San Severino Marche (gained territory from the suppressed Diocese of San Severino and became suffragan of Fermo) |
| 1986.09.30 | Diocese of Campagna was suppressed (to Metropolitan Archdiocese of Salerno–Campagna–Acerno) |
| 1986.09.30 | Diocese of Cariati was suppressed (to Archdiocese of Rossano–Cariati) |
| 1986.09.30 | Diocese of Castellammare di Stabia was suppressed (to Archdiocese of Sorrento–Castellammare di Stabia) |
| 1986.09.30 | Archdiocese of Catanzaro was renamed as Archdiocese of Catanzaro–Squillace (gained territory from Diocese of Nicastro and gained territory from the suppressed Diocese of Squillace) |
| 1986.09.30 | Diocese of Cava de’ Tirreni was suppressed (to Archdiocese of Amalfi–Cava de’ Tirreni) |
| 1986.09.30 | Diocese of Cerignola was renamed as Diocese of Cerignola–Ascoli Satriano (gained territory from the suppressed Diocese of Ascoli Satriano) |
| 1986.09.30 | Diocese of Telese was renamed as Diocese of Cerreto Sannita–Telese–Sant’Agata de’ Goti (gained territory from the suppressed Diocese of Sant’Agata de’ Goti) |
| 1986.09.30 | Diocese of Cervia was suppressed (to Metropolitan Archdiocese of Ravenna–Cervia) |
| 1986.09.30 | Diocese of Cesena was renamed as Diocese of Cesena–Sarsina (gained territory from the suppressed Diocese of Sarsina) |
| 1986.09.30 | Metropolitan Archdiocese of Chieti was renamed as Metropolitan Archdiocese of Chieti–Vasto (gained territory from the suppressed Diocese of Vasto and lost suffragan see Ortona) |
| 1986.09.30 | Diocese of Chiusi was suppressed (to Diocese of Montepulciano–Chiusi–Pienza) |
| 1986.09.30 | Diocese of Cingoli was suppressed (to Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 1986.09.30 | Diocese of Città della Pieve was suppressed (to Metropolitan Archdiocese of Perugia–Città della Pieve) |
| 1986.09.30 | Diocese of Civitavecchia was renamed as Diocese of Civitavecchia–Tarquinia (gained territory from the suppressed Diocese of Tarquinia) |
| 1986.09.30 | Diocese of Civita–Tempio was suppressed (to establish Diocese of Tempio–Ampurias) |
| 1986.09.30 | Diocese of Colle di Val d’Elsa was suppressed (to Metropolitan Archdiocese of Siena–Colle di Val d’Elsa–Montalcino) |
| 1986.09.30 | Diocese of Comacchio was suppressed (to Archdiocese of Ferrara–Comacchio and lost title of Pomposa) |
| 1986.09.30 | Diocese of Conversano was renamed as Diocese of Conversano–Monopoli (gained territory from the suppressed Diocese of Monopoli) |
| 1986.09.30 | Archdiocese of Conza was suppressed (to Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia) |
| 1986.09.30 | Diocese of Cortona was suppressed (to Diocese of Arezzo–Cortona–Sansepolcro) |
| 1986.09.30 | Archdiocese of Cosenza was renamed as Archdiocese of Cosenza–Bisignano (gained territory from Diocese of Nicastro and gained territory from the suppressed Diocese of Bisignano) |
| 1986.09.30 | Diocese of Crotone was promoted as Archdiocese of Crotone–Santa Severina (gained territory from the suppressed Archdiocese of Santa Severina) |
| 1986.09.30 | Diocese of Fabriano was renamed as Diocese of Fabriano–Matelica (gained territory from the suppressed Diocese of Matelica) |
| 1986.09.30 | Diocese of Faenza was renamed as Diocese of Faenza–Modigliana (gained territory from the suppressed Diocese of Modigliana) |
| 1986.09.30 | Diocese of Fano was renamed as Diocese of Fano–Fossombrone–Cagli–Pergola (gained territory from the suppressed Diocese of Cagli, Diocese of Fossombrone and Diocese of Pergola and became suffragan of Urbino–Urbania–Sant’Angelo in Vado) |
| 1986.09.30 | Diocese of Feltre was suppressed (to Diocese of Belluno–Feltre) |
| 1986.09.30 | Diocese of Ferentino was suppressed (to Diocese of Frosinone–Veroli–Ferentino) |
| 1986.09.30 | Archdiocese of Ferrara was renamed as Archdiocese of Ferrara–Comacchio (gained territory from the suppressed Diocese of Comacchio and gained title of Pomposa) |
| 1986.09.30 | Metropolitan Archdiocese of Foggia was renamed as Metropolitan Archdiocese of Foggia–Bovino (gained territory from Archdiocese of Manfredonia, gained territory from the suppressed Diocese of Bovino and lost suffragan sees Ascoli Satriano, Troia and Vieste) |
| 1986.09.30 | Diocese of Forlì was renamed as Diocese of Forlì–Bertinoro (gained territory from the suppressed Diocese of Bertinoro and Diocese of Modigliana) |
| 1986.09.30 | Diocese of Fossombrone was suppressed (to Diocese of Fano–Fossombrone–Cagli–Pergola) |
| 1986.09.30 | Diocese of Veroli–Frosinone was renamed as Diocese of Frosinone–Veroli–Ferentino (gained territory from the suppressed Diocese of Ferentino) |
| 1986.09.30 | Diocese of Gallipoli was suppressed (to Diocese of Nardò–Gallipoli) |
| 1986.09.30 | Metropolitan Archdiocese of Genova was renamed as Metropolitan Archdiocese of Genova–Bobbio (gained territory from the suppressed Diocese of Bobbio–San Colombano and lost suffragan sees Bobbio–San Colombano, Brugnato and Noli) |
| 1986.09.30 | Diocese of Giovinazzo was suppressed (to Diocese of Molfetta–Ruvo–Giovinazzo–Terlizzi) |
| 1986.09.30 | Metropolitan Archdiocese of Gorizia e Gradisca was renamed as Metropolitan Archdiocese of Gorizia (lost territory to establish Titular Archiepiscopal See of Gradisca) |
| 1986.09.30 | Titular Archiepiscopal See of Gradisca was restored (from Metropolitan Archdiocese of Gorizia e Gradisca) |
| 1986.09.30 | Diocese of Gravina was suppressed (to Diocese of Altamura–Gravina–Acquaviva delle Fonti) |
| 1986.09.30 | Diocese of Guastalla was suppressed (to Diocese of Reggio Emilia–Guastalla) |
| 1986.09.30 | Diocese of Irsina was suppressed (to Archdiocese of Matera–Irsina) |
| 1986.09.30 | Diocese of Isernia was renamed as Diocese of Isernia–Venafro (gained territory from the suppressed Diocese of Venafro) |
| 1986.09.30 | Diocese of La Spezia was renamed as Diocese of La Spezia–Sarzana–Brugnato (gained territory from the suppressed Diocese of Brugnato and Diocese of Sarzana) |
| 1986.09.30 | Diocese of Lacedonia was suppressed (to Diocese of Ariano Irpino–Lacedonia) |
| 1986.09.30 | Diocese of Nicastro was renamed as Diocese of Lamezia Terme (lost territory to Archdiocese of Catanzaro–Squillace, Archdiocese of Cosenza–Bisignano and Diocese of Mileto–Nicotera–Tropea) |
| 1986.09.30 | Archdiocese of Lanciano was renamed as Archdiocese of Lanciano–Ortona (gained territory from the suppressed Diocese of Ortona) |
| 1986.09.30 | Diocese of Ogliastra was renamed as Diocese of Lanusei |
| 1986.09.30 | Diocese of Larino was suppressed (to Diocese of Termoli–Larino) |
| 1986.09.30 | Diocese of Terracina–Latina was renamed as Diocese of Latina–Terracina–Sezze–Priverno (gained territory from the suppressed Diocese of Priverno and Diocese of Sezze) |
| 1986.09.30 | Diocese of Lipari was suppressed (to Metropolitan Archdiocese of Messina–Lipari–Santa Lucia del Mela) |
| 1986.09.30 | Diocese of Gerace–Locri was renamed as Diocese of Locri–Gerace |
| 1986.09.30 | Diocese of Lucera was renamed as Diocese of Lucera–Troia (gained territory from the suppressed Diocese of Troia and lost territory to Diocese of San Severo) |
| 1986.09.30 | Diocese of Macerata was renamed as Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia (gained territory from the suppressed Diocese of Cingoli, Diocese of Recanati, Diocese of Tolentino and Diocese of Treia) |
| 1986.09.30 | Archdiocese of Manfredonia was renamed as Archdiocese of Manfredonia–Vieste (gained territory from the suppressed Diocese of Vieste and lost territory to Metropolitan Archdiocese of Foggia–Bovino and Diocese of San Severo) |
| 1986.09.30 | Diocese of Marsico Nuovo was suppressed (to Metropolitan Archdiocese of Potenza–Muro Lucano–Marsico Nuovo) |
| 1986.09.30 | Diocese of Apuania was renamed as Diocese of Massa |
| 1986.09.30 | Diocese of Matelica was suppressed (to Diocese of Fabriano–Matelica) |
| 1986.09.30 | Archdiocese of Matera was renamed as Archdiocese of Matera–Irsina (gained territory from the suppressed Diocese of Irsina) |
| 1986.09.30 | Diocese of Melfi was renamed as Diocese of Melfi–Rapolla–Venosa (gained territory from the suppressed Diocese of Rapolla and Diocese of Venosa) |
| 1986.09.30 | Metropolitan Archdiocese of Messina was renamed as Metropolitan Archdiocese of Messina–Lipari–Santa Lucia del Mela (gained territory from the suppressed Diocese of Lipari, Territorial Prelature of Santa Lucia del Mela and Territorial Abbacy of Santissimo Salvatore and gained title of Santissimo Salvatore) |
| 1986.09.30 | Diocese of Mileto was renamed as Diocese of Mileto–Nicotera–Tropea (gained territory from Diocese of Nicastro, gained territory from the suppressed Diocese of Nicotera and Diocese of Tropea, lost territory to Diocese of Oppido Mamertina–Palmi and became suffragan of Reggio Calabria–Bova) |
| 1986.09.30 | Metropolitan Archdiocese of Modena was renamed as Metropolitan Archdiocese of Modena–Nonantola (gained territory from the suppressed Abbacy nullius of Nonantola, lost title of Nonantola and lost suffragan sees Guastalla and Nonantola) |
| 1986.09.30 | Diocese of Modigliana was suppressed (to Diocese of Faenza–Modigliana and Diocese of Forlì–Bertinoro) |
| 1986.09.30 | Diocese of Molfetta was renamed as Diocese of Molfetta–Ruvo–Giovinazzo–Terlizzi (gained territory from the suppressed Diocese of Giovinazzo, Diocese of Ruvo and Diocese of Terlizzi) |
| 1986.09.30 | Diocese of Monopoli was suppressed (to Diocese of Conversano–Monopoli) |
| 1986.09.30 | Diocese of Montalcino was suppressed (to Metropolitan Archdiocese of Siena–Colle di Val d’Elsa–Montalcino) |
| 1986.09.30 | Diocese of Montalto was suppressed (to Diocese of San Benedetto del Tronto–Ripatransone–Montalto) |
| 1986.09.30 | Diocese of Montepulciano was renamed as Diocese of Montepulciano–Chiusi–Pienza (gained territory from the suppressed Diocese of Chiusi and Diocese of Pienza, lost territory to Diocese of Arezzo–Cortona–Sansepolcro and became suffragan of Siena–Colle di Val d’Elsa–Montalcino) |
| 1986.09.30 | Diocese of Muro Lucano was suppressed (to Metropolitan Archdiocese of Potenza–Muro Lucano–Marsico Nuovo) |
| 1986.09.30 | Diocese of Nardò was renamed as Diocese of Nardò–Gallipoli (gained territory from the suppressed Diocese of Gallipoli) |
| 1986.09.30 | Diocese of Narni was suppressed (to Diocese of Terni–Narni–Amelia) |
| 1986.09.30 | Diocese of Nicotera was suppressed (to Diocese of Mileto–Nicotera–Tropea) |
| 1986.09.30 | Diocese of Nocera de’ Pagani was renamed as Diocese of Nocera Inferiore–Sarno (gained territory from the suppressed Diocese of Sarno) |
| 1986.09.30 | Diocese of Nocera Umbra–Gualdo Tadino was suppressed (to Diocese of Assisi–Nocera Umbra–Gualdo Tadino) |
| 1986.09.30 | Diocese of Noli was suppressed (to Diocese of Savona–Noli) |
| 1986.09.30 | Abbacy nullius of Nonantola was suppressed (to Metropolitan Archdiocese of Modena–Nonantola and no longer united) |
| 1986.09.30 | Diocese of Norcia was suppressed (to Archdiocese of Spoleto–Norcia) |
| 1986.09.30 | Diocese of Nusco was suppressed (to Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia) |
| 1986.09.30 | Diocese of Ortona was suppressed (to Archdiocese of Lanciano–Ortona) |
| 1986.09.30 | Diocese of Orvieto was renamed as Diocese of Orvieto–Todi (gained territory from the suppressed Diocese of Todi) |
| 1986.09.30 | Diocese of Osimo was suppressed (to Metropolitan Archdiocese of Ancona–Osimo) |
| 1986.09.30 | Diocese of Ostuni was suppressed (to Archdiocese of Brindisi–Ostuni) |
| 1986.09.30 | Diocese of Pergola was suppressed (to Diocese of Fano–Fossombrone–Cagli–Pergola) |
| 1986.09.30 | Metropolitan Archdiocese of Perugia was renamed as Metropolitan Archdiocese of Perugia–Città della Pieve (gained territory from the suppressed Diocese of Città della Pieve and lost suffragan sees Città della Pieve and Nocera Umbra–Gualdo Tadino) |
| 1986.09.30 | Diocese of Pienza was suppressed (to Diocese of Montepulciano–Chiusi–Pienza) |
| 1986.09.30 | Diocese of Sovana–Pitigliano–Orbetello was renamed as Diocese of Pitigliano–Sovana–Orbetello |
| 1986.09.30 | Diocese of Policastro was suppressed (to Diocese of Teggiano–Policastro) |
| 1986.09.30 | Diocese of Pontecorvo was suppressed (to Diocese of Sora–Aquino–Pontecorvo) |
| 1986.09.30 | Diocese of Porto e Santa Rufina was renamed as Diocese of Porto–Santa Rufina |
| 1986.09.30 | Metropolitan Archdiocese of Potenza was renamed as Metropolitan Archdiocese of Potenza–Muro Lucano–Marsico Nuovo (gained territory from the suppressed Diocese of Marsico Nuovo and Diocese of Muro Lucano and lost suffragan sees Marsico Nuovo, Muro Lucano, Rapolla and Venosa) |
| 1986.09.30 | Diocese of Priverno was suppressed (to Diocese of Latina–Terracina–Sezze–Priverno) |
| 1986.09.30 | Diocese of Rapolla was suppressed (to Diocese of Melfi–Rapolla–Venosa) |
| 1986.09.30 | Metropolitan Archdiocese of Ravenna was renamed as Metropolitan Archdiocese of Ravenna–Cervia (gained territory from the suppressed Diocese of Cervia and lost suffragan sees Cervia and Sarsina) |
| 1986.09.30 | Diocese of Recanati was suppressed (to Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 1986.09.30 | Metropolitan Archdiocese of Reggio Calabria was renamed as Metropolitan Archdiocese of Reggio Calabria–Bova (gained territory from the suppressed Diocese of Bova, lost suffragan sees Cariati, Nicotera, Squillace and Tropea and gained suffragan sees Rossano–Cariati and Mileto–Nicotera–Tropea) |
| 1986.09.30 | Diocese of Reggio Emilia was renamed as Diocese of Reggio Emilia–Guastalla (gained territory from the suppressed Diocese of Guastalla) |
| 1986.09.30 | Archdiocese of Rossano was renamed as Archdiocese of Rossano–Cariati (gained territory from the suppressed Diocese of Cariati and became suffragan of Reggio Calabria–Bova) |
| 1986.09.30 | Diocese of Ruvo was suppressed (to Diocese of Molfetta–Ruvo–Giovinazzo–Terlizzi) |
| 1986.09.30 | Diocese of Sabina e Poggio Mirteto was renamed as Diocese of Sabina–Poggio Mirteto |
| 1986.09.30 | Metropolitan Archdiocese of Salerno was renamed as Metropolitan Archdiocese of Salerno–Campagna–Acerno (gained territory from the suppressed Diocese of Acerno and Diocese of Campagna and lost suffragan sees Acerno, Cava de’ Tirreni, Policastro and Sarno) |
| 1986.09.30 | Diocese of Ripatransone–San Benedetto del Tronto was renamed as Diocese of San Benedetto del Tronto–Ripatransone–Montalto (gained territory from the suppressed Diocese of Montalto) |
| 1986.09.30 | Diocese of San Severino was suppressed (to Archdiocese of Camerino–San Severino Marche) |
| 1986.09.30 | Diocese of Sansepolcro was suppressed (to Diocese of Arezzo–Cortona–Sansepolcro) |
| 1986.09.30 | Territorial Prelature of Santa Lucia del Mela was suppressed (to Metropolitan Archdiocese of Messina–Lipari–Santa Lucia del Mela) |
| 1986.09.30 | Archdiocese of Santa Severina was suppressed (to Archdiocese of Crotone–Santa Severina) |
| 1986.09.30 | Territorial Abbacy of Santissimo Salvatore (Italo-Albanese Rite) was suppressed (to Metropolitan Archdiocese of Messina–Lipari–Santa Lucia del Mela and united to Metropolitan Archdiocese of Messina) |
| 1986.09.30 | Diocese of Sant’Agata de’ Goti was suppressed (to Diocese of Cerreto Sannita–Telese–Sant’Agata de’ Goti) |
| 1986.09.30 | Diocese of Sant’Angelo dei Lombardi was promoted as Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia (gained territory from the suppressed Archdiocese of Conza, Diocese of Bisaccia and Diocese of Nusco) |
| 1986.09.30 | Diocese of Sant’Angelo in Vado was suppressed (to Metropolitan Archdiocese of Urbino–Urbania–Sant’Angelo in Vado) |
| 1986.09.30 | Diocese of Sarno was suppressed (to Diocese of Nocera Inferiore–Sarno) |
| 1986.09.30 | Diocese of Sarsina was suppressed (to Diocese of Cesena–Sarsina) |
| 1986.09.30 | Diocese of Sarzana was suppressed (to Diocese of La Spezia–Sarzana–Brugnato) |
| 1986.09.30 | Diocese of Savona was renamed as Diocese of Savona–Noli (gained territory from the suppressed Diocese of Noli) |
| 1986.09.30 | Diocese of Segni was suppressed (to Diocese of Velletri–Segni) |
| 1986.09.30 | Diocese of Sezze was suppressed (to Diocese of Latina–Terracina–Sezze–Priverno) |
| 1986.09.30 | Metropolitan Archdiocese of Siena was renamed as Metropolitan Archdiocese of Siena–Colle di Val d’Elsa–Montalcino (gained territory from the suppressed Diocese of Colle di Val d’Elsa and Diocese of Montalcino, lost suffragan see Chiusi and gained suffragan see Montepulciano–Chiusi–Pienza) |
| 1986.09.30 | Diocese of Sora was renamed as Diocese of Sora–Aquino–Pontecorvo (gained territory from the suppressed Diocese of Aquino and Diocese of Pontecorvo) |
| 1986.09.30 | Archdiocese of Sorrento was renamed as Archdiocese of Sorrento–Castellammare di Stabia (gained territory from the suppressed Diocese of Castellammare di Stabia) |
| 1986.09.30 | Archdiocese of Spoleto was renamed as Archdiocese of Spoleto–Norcia (gained territory from the suppressed Diocese of Norcia) |
| 1986.09.30 | Diocese of Squillace was suppressed (to Archdiocese of Catanzaro–Squillace) |
| 1986.09.30 | Diocese of Sulmona was renamed as Diocese of Sulmona–Valva (gained territory from the suppressed Diocese of Valva) |
| 1986.09.30 | Diocese of Tarquinia was suppressed (to Diocese of Civitavecchia–Tarquinia) |
| 1986.09.30 | Diocese of Teano was renamed as Diocese of Teano–Calvi (gained territory from the suppressed Diocese of Calvi) |
| 1986.09.30 | Diocese of Diano–Teggiano was renamed as Diocese of Teggiano–Policastro (gained territory from the suppressed Diocese of Policastro) |
| 1986.09.30 | Diocese of Tempio–Ampurias was established (from the suppressed Diocese of Ampurias and Diocese of Civita–Tempio and became suffragan of Sassari) |
| 1986.09.30 | Diocese of Teramo was renamed as Diocese of Teramo–Atri (gained territory from the suppressed Diocese of Atri) |
| 1986.09.30 | Diocese of Terlizzi was suppressed (to Diocese of Molfetta–Ruvo–Giovinazzo–Terlizzi) |
| 1986.09.30 | Diocese of Termoli was renamed as Diocese of Termoli–Larino (gained territory from the suppressed Diocese of Larino) |
| 1986.09.30 | Diocese of Terni was renamed as Diocese of Terni–Narni–Amelia (gained territory from the suppressed Diocese of Amelia and Diocese of Narni) |
| 1986.09.30 | Diocese of Terralba was suppressed (to Diocese of Ales–Terralba) |
| 1986.09.30 | Diocese of Todi was suppressed (to Diocese of Orvieto–Todi) |
| 1986.09.30 | Diocese of Tolentino was suppressed (to Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 1986.09.30 | Archdiocese of Trani was renamed as Archdiocese of Trani–Barletta–Bisceglie (gained territory from the suppressed Archdiocese of Barletta and Diocese of Bisceglie) |
| 1986.09.30 | Diocese of Treia was suppressed (to Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 1986.09.30 | Diocese of Troia was suppressed (to Diocese of Lucera–Troia) |
| 1986.09.30 | Diocese of Tropea was suppressed (to Diocese of Mileto–Nicotera–Tropea) |
| 1986.09.30 | Diocese of Urbania was suppressed (to Metropolitan Archdiocese of Urbino–Urbania–Sant’Angelo in Vado) |
| 1986.09.30 | Metropolitan Archdiocese of Urbino was renamed as Metropolitan Archdiocese of Urbino–Urbania–Sant’Angelo in Vado (gained territory from the suppressed Diocese of Sant’Angelo in Vado and Diocese of Urbania, lost suffragan see Cagli and gained suffragan see Fano–Fossombrone–Cagli–Pergola) |
| 1986.09.30 | Diocese of Vallo di Lucania was renamed as Diocese of Vallo della Lucania |
| 1986.09.30 | Diocese of Valva was suppressed (to Diocese of Sulmona–Valva) |
| 1986.09.30 | Diocese of Vasto was suppressed (to Metropolitan Archdiocese of Chieti–Vasto) |
| 1986.09.30 | Diocese of Velletri was renamed as Diocese of Velletri–Segni (gained territory from the suppressed Diocese of Segni) |
| 1986.09.30 | Diocese of Venafro was suppressed (to Diocese of Isernia–Venafro) |
| 1986.09.30 | Diocese of Venosa was suppressed (to Diocese of Melfi–Rapolla–Venosa) |
| 1986.09.30 | Diocese of Vieste was suppressed (to Archdiocese of Manfredonia–Vieste) |
| 1986.09.30 | Diocese of Viterbo was renamed as Diocese of Viterbo, Acquapendente, Bagnoregio, Montefiascone, Tuscania e San Martino al Monte Cimino (gained territory from the suppressed Diocese of Acquapendente and Diocese of Bagnoregio) |
| 1988 | Archdiocese of Amalfi–Cava de’ Tirreni lost territory to Metropolitan Archdiocese of Salerno–Campagna–Acerno |
| 1988 | Diocese of Nardò–Gallipoli lost territory to Archdiocese of Otranto |
| 1988 | Archdiocese of Otranto lost territory to Metropolitan Archdiocese of Lecce and Diocese of Ugento–Santa Maria di Leuca |
| 1988.02.23 | Diocese of Massa was renamed as Diocese of Massa Carrara–Pontremoli (gained territory from the suppressed Diocese of Pontremoli) |
| 1988.02.23 | Diocese of Pontremoli was suppressed (to Diocese of Massa Carrara–Pontremoli) |
| 1989.03.03 | Metropolitan Archdiocese of Milano (Ambrosian Rite) lost territory to Diocese of Lodi |
| 1989.09.16 | Metropolitan Archdiocese of Genova–Bobbio was renamed as Metropolitan Archdiocese of Genova (lost territory to Diocese of Chiavari and Diocese of Piacenza–Bobbio) |
| 1989.09.16 | Diocese of Piacenza was renamed as Diocese of Piacenza–Bobbio (gained territory from Metropolitan Archdiocese of Genova–Bobbio) |
| 1989.11.18 | Archdiocese of Catanzaro–Squillace exchanged territory with Diocese of Locri–Gerace |
| 1989.11.18 | Archdiocese of Cosenza–Bisignano lost territory to Archdiocese of Catanzaro–Squillace |
| 1989.11.18 | Archdiocese of Crotone–Santa Severina lost territory to Archdiocese of Catanzaro–Squillace |
| 1989.11.18 | Diocese of Locri–Gerace exchanged territory with Archdiocese of Catanzaro–Squillace |
| 1990 | Diocese of Fano–Fossombrone–Cagli–Pergola lost territory to Metropolitan Archdiocese of Urbino–Urbania–Sant’Angelo in Vado |
| 1990 | Titular Episcopal See of Foro Flaminii was renamed as Titular Episcopal See of Foro Flaminio |
| 1991 | Titular Episcopal See of Acquapendente was restored |
| 1991 | Titular Episcopal See of Bagnoregio was restored |
| 1991 | Titular Episcopal See of Gallese was restored |
| 1991 | Titular Episcopal See of Nepi was restored |
| 1991 | Titular Episcopal See of Orte was restored |
| 1991 | Titular Episcopal See of Sutri was restored |
| 1991 | Titular Episcopal See of Tuscania was restored |
| 1991.02.16 | Titular Episcopal See of Montefiascone was restored |
| 1991.02.16 | Diocese of Viterbo, Acquapendente, Bagnoregio, Montefiascone, Tuscania e San Martino al Monte Cimino was renamed as Diocese of Viterbo |
| 1991.03.25 | Diocese of Albano exchanged territory with Diocese of Latina–Terracina–Sezze–Priverno |
| 1991.03.25 | Diocese of Latina–Terracina–Sezze–Priverno exchanged territory with Diocese of Albano |
| 1992.06.29 | Diocese of Civita Castellana lost territory to Diocese of Terni–Narni–Amelia |
| 1992.09.05 | Diocese of Massa Carrara–Pontremoli lost territory to Archdiocese of Lucca |
| 1994 | Diocese of San Severo lost territory to Metropolitan Archdiocese of Foggia–Bovino |
| 1995 | Titular Episcopal See of Thurio was restored |
| 1995.10.18 | Diocese of Avellino lost territory to Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia |
| 1997 | Titular Episcopal See of Bisarcio was restored |
| 1997.03.06 | Diocese of Ariano Irpino–Lacedonia exchanged territory with Metropolitan Archdiocese of Benevento |
| 1997.03.06 | Metropolitan Archdiocese of Benevento exchanged territory with Diocese of Ariano Irpino–Lacedonia |
| 1997.11.18 | Archdiocese of Cosenza–Bisignano lost territory to Diocese of San Marco Argentano–Scalea |
| 1998.01.25 | Diocese of Ariano Irpino–Lacedonia exchanged territory with Metropolitan Archdiocese of Benevento |
| 1998.01.25 | Diocese of Avellino lost territory to Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia and Diocese of Ariano Irpino–Lacedonia |
| 1998.01.25 | Metropolitan Archdiocese of Benevento lost territory to Diocese of Avellino |
| 1998.01.25 | Metropolitan Archdiocese of Salerno–Campagna–Acerno lost territory to Diocese of Avellino |
| 1998.01.25 | Archdiocese of Sant’Angelo dei Lombardi–Conza–Nusco–Bisaccia lost territory to Metropolitan Archdiocese of Potenza–Muro Lucano–Marsico Nuovo and Diocese of Ariano Irpino–Lacedonia |
| 2000.03.11 | Diocese of Pesaro was promoted as Metropolitan Archdiocese of Pesaro (with suffragan sees Urbino–Urbania–Sant’Angelo in Vado and Fano–Fossombrone–Cagli–Pergola) |
| 2000.03.11 | Metropolitan Archdiocese of Urbino–Urbania–Sant’Angelo in Vado was demoted as Archdiocese of Urbino–Urbania–Sant’Angelo in Vado (became suffragan of Pesaro) |
| 2000.12.02 | Diocese of Agrigento was promoted as Metropolitan Archdiocese of Agrigento (with suffragan sees Caltanissetta and Piazza Armerina) |
| 2000.12.02 | Archdiocese of Catania was promoted as Metropolitan Archdiocese of Catania (with suffragan sees Acireale and Caltagirone) |
| 2000.12.02 | Metropolitan Archdiocese of Monreale was demoted as Archdiocese of Monreale (became suffragan of Palermo) |
| 2001.01.30 | Archdiocese of Catanzaro–Squillace was promoted as Metropolitan Archdiocese of Catanzaro–Squillace (with suffragan sees Crotone–Santa Severina and Lamezia Terme) |
| 2001.01.30 | Archdiocese of Cosenza–Bisignano was promoted as Metropolitan Archdiocese of Cosenza–Bisignano (with suffragan sees Rossano–Cariati, Cassano all’Jonio and San Marco Argentano–Scalea) |
| 2001.04.27 | Diocese of Cremona lost territory to Diocese of Crema |
| 2002 | Titular Episcopal See of Canosa was restored |
| 2002.07.16 | Territorial Abbacy of Subiaco lost territory to Diocese of Anagni–Alatri, Diocese of Palestrina and Diocese of Tivoli |
| 2002.12.06 | Archdiocese of Manfredonia–Vieste was renamed as Archdiocese of Manfredonia–Vieste–San Giovanni Rotondo |
| 2003.01.14 | Diocese of Fidenza exchanged territory with Diocese of Parma and Diocese of Piacenza–Bobbio |
| 2003.01.14 | Diocese of La Spezia–Sarzana–Brugnato lost territory to Diocese of Massa Carrara–Pontremoli |
| 2003.01.14 | Diocese of Massa Carrara–Pontremoli lost territory to Diocese of Piacenza–Bobbio |
| 2003.01.14 | Diocese of Parma exchanged territory with Diocese of Fidenza and Diocese of Piacenza–Bobbio |
| 2003.01.14 | Diocese of Piacenza–Bobbio exchanged territory with Diocese of Fidenza and Diocese of Parma |
| 2004.05 | Titular Episcopal See of Arna was restored |
| 2004.06 | Titular Episcopal See of Biccari was restored |
| 2004.06 | Titular Episcopal See of Carmeiano was restored |
| 2004.06 | Titular Episcopal See of Egnazia Appula was restored |
| 2004.06 | Titular Episcopal See of Erdonia was restored |
| 2004.10 | Titular Episcopal See of Galtellì was restored |
| 2004.10 | Titular Episcopal See of Ostra was restored |
| 2004.10 | Titular Episcopal See of Ottana was restored |
| 2005.03.07 | Territorial Abbacy of San Paolo fuori le Mura was suppressed (to Papal See of Roma) |
| 2005.05.15 | Territorial Abbacy of Montevergine lost territory to Diocese of Avellino |
| 2009.01 | Titular Episcopal See of Aveia was restored |
| 2009.01 | Titular Episcopal See of Celano was restored |
| 2009.01 | Titular Episcopal See of Sepino was restored |
| 2010.05.31 | Metropolitan Archdiocese of Pescara–Penne lost territory to Metropolitan Archdiocese of Chieti–Vasto |
| 2012.07.17 | Papal See of Roma lost territory to Diocese of Ostia |
| 2012.08.20 | Territorial Abbacy of Santissima Trinità di Cava de’ Tirreni lost territory to Archdiocese of Amalfi–Cava de’ Tirreni |
| 2014.08.08 | Diocese of Verona lost territory to Diocese of Vicenza |
| 2014.10.23 | Territorial Abbacy of Montecassino lost territory to Diocese of Sora–Cassino–Aquino–Pontecorvo |
| 2014.10.23 | Diocese of Sora–Aquino–Pontecorvo was renamed as Diocese of Sora–Cassino–Aquino–Pontecorvo (gained territory from Territorial Abbacy of Montecassino) |
| 2016.06.26 | Diocese of Novara exchanged territory with Diocese of Vigevano |
| 2016.06.26 | Diocese of Vigevano exchanged territory with Diocese of Novara |
| 2017.07.15 | Diocese of Arezzo–Cortona–Sansepolcro lost territory to Metropolitan Archdiocese of Perugia–Città della Pieve |
| 2017.12 | Titular Episcopal See of Amantea was restored |
| 2017.12 | Titular Episcopal See of Limosano was restored |
| 2017.12 | Titular Episcopal See of Malamocco was restored |
| 2018.01 | Titular Episcopal See of Bisenzio was restored |
| 2018.01 | Titular Episcopal See of Milazzo was restored |
| 2018.01 | Titular Episcopal See of Rosella was restored |
| 2018.03 | Titular Episcopal See of Alesa was restored |
| 2018.06.29 | Patriarchal See of Venezia lost territory to Diocese of Concordia–Pordenone |
| 2019.07.11 | Apostolic Exarchate of Italy (Ukrainian Rite) was established |
| 2022.07.14 | Personal Prelature of Opus Dei was suppressed (to establish Opus Dei) |
| 2022.12.17 | Titular Episcopal See of Cingoli was restored (from Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 2022.12.17 | Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia was renamed as Diocese of Macerata (lost territory to establish Titular Episcopal See of Cingoli, Titular Episcopal See of Recanati, Titular Episcopal See of Tolentino and Titular Episcopal See of Treia) |
| 2022.12.17 | Titular Episcopal See of Recanati was restored (from Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 2022.12.17 | Titular Episcopal See of Tolentino was restored (from Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 2022.12.17 | Titular Episcopal See of Treia was restored (from Diocese of Macerata–Tolentino–Recanati–Cingoli–Treia) |
| 2023.06.01 | Diocese of Cuneo was renamed as Diocese of Cuneo–Fossano (gained territory from the suppressed Diocese of Fossano) |
| 2023.06.01 | Diocese of Fossano was suppressed (to Diocese of Cuneo–Fossano) |