| Date | From | To |
|---|
| unknown | Delegation to Mesopotamia, Kurdistan, and Lesser Armenia, Iraq
| Name Changed | Delegation to Iraq
| Name Changed |
| 3 Jan | Diocese of Sault Sainte Marie and Marquette, Michigan, USA
| Name Changed | Diocese of Marquette, Michigan, USA
| Name Changed |
| 5 Jan | Diocese of Savannah, Georgia, USA
| Name Changed | Diocese of Savannah-Atlanta, Georgia, USA
| Name Changed |
| 4 Feb | Vicariate Apostolic of Lanchowfu, China (Tsinghai)
| Territory Lost | Prefecture Apostolic of Xining [Sining], China
| Erected |
| 13 Feb | Diocese of Santa Maria, Rio Grande do Sul, Brazil (Rio Pardo and Candelaria)
| Territory Lost | Archdiocese of Porto Alegre, Rio Grande do Sul, Brazil
| Territory Added |
| 22 Feb | Vicariate Apostolic of Buta, Congo (Dem. Rep.) (Lolo and Moenge)
| Territory Lost | Prefecture Apostolic of Lolo, Congo (Dem. Rep.)
| Erected |
| 22 Feb | Vicariate Apostolic of Wuhu [Wuhu], China (Tsiki, ñhenhsien, Siuning, Kimen, Ihsien in the civil province of Anhwei, as well as the civil sub-prefecture of Wuyuan in the civil province of Kiangsi)
| Territory Lost | Prefecture Apostolic of Tunxi [Tunki], China
| Erected |
| 27 Feb | | | Diocese of Pembroke, Ontario, Canada (Boundaries adjusted)
Diocese of Sault Sainte Marie, Ontario, Canada (Boundaries adjusted)
| Territory Added |
| 9 Mar | Vicariate Apostolic of Bamako, Mali (French Guinea)
| Territory Lost | Prefecture Apostolic of N’Zérékoré, Guinea
| Erected |
| 9 Mar | Vicariate Apostolic of Bobo-Dioulasso, Burkina Faso (Dmvdougou and Belekouo)
| Territory Lost | Vicariate Apostolic of Bamako, Mali
| Territory Added |
| 9 Mar | Vicariate Apostolic of Ouagadougou, Burkina Faso (Dagari de Niego and Dagari de Bozo)
| Territory Lost | Vicariate Apostolic of Bobo-Dioulasso, Burkina Faso
| Territory Added |
| 9 Mar | Prefecture Apostolic of Bobo-Dioulasso, Burkina Faso
| Elevated | Vicariate Apostolic of Bobo-Dioulasso, Burkina Faso
| Elevated |
| 20 Mar | Diocese of Osimo e Cingoli, Italy (S. Maria ab Ulmo)
| Territory Lost | Diocese of Jesi, Italy
| Territory Added |
| 20 Mar | | | Archdiocese of Saint-Boniface, Manitoba, Canada (Boundaries adjusted to match civil boundaries)
Archdiocese of Winnipeg, Manitoba, Canada (Boundaries adjusted to match civil boundaries)
| Territory Added |
| 25 Mar | Vicariate Apostolic of Galla, Ethiopia
Prefecture Apostolic of Kaffa, Ethiopia
| Territory Lost | Prefecture Apostolic of Neghelli, Ethiopia (Sidamo and Borana (in Galla and Sidamo))
| Erected |
| 25 Mar | Vicariate Apostolic of Galla, Ethiopia
| Name Changed | Vicariate Apostolic of Harar, Ethiopia
| Name Changed |
| 25 Mar | Prefecture Apostolic of Kaffa, Ethiopia
| Elevated | Vicariate Apostolic of Gimma, Ethiopia (and Name Changed)
| Elevated |
| 25 Mar | Vicariate Apostolic of Abyssinia, Ethiopia (Uolio? and Debre Berhan)
| Territory Lost | Prefecture Apostolic of Dessié, Ethiopia
| Erected |
| 25 Mar | Vicariate Apostolic of Abyssinia, Ethiopia (Gondar, Semien, Gojjam, and Begemder)
| Territory Lost | Prefecture Apostolic of Gondar, Ethiopia
| Erected |
| 25 Mar | Vicariate Apostolic of Abyssinia, Ethiopia (Adwa, Mekelle, Adigrat, Abiy Addi, and Alamata)
| Territory Lost | Prefecture Apostolic of Tigrai, Ethiopia
| Erected |
| 25 Mar | Vicariate Apostolic of Abyssinia, Ethiopia
| Territory Lost | Vicariate Apostolic of Addis Abeba, Ethiopia (Addis Abeba)
| Erected |
| 25 Mar | Delegation to Egypt, Arabia, Eritrea, Ethiopia, Palestine, TransJordan, and Island of Cyprus
| Established | Delegation to Italian East Africa, Ethiopia
| Established |
| 25 Mar | Delegation to Egypt, Arabia, Eritrea, Ethiopia, Palestine, TransJordan, and Island of Cyprus
| Name Changed | Delegation to Egypt and Arabia
| Name Changed |
| 25 Mar | | | Vicariate Apostolic of Mogadiscio, Somalia (Boundaries adjusted to now cover Somalia and no more)
| Territory Added |
| 25 Mar | | | Prefecture Apostolic of Djibouti (Gibuti) (Boundaries adjusted to now cover French Somalia and no more)
| Territory Added |
| 13 Apr | Vicariate Apostolic of Central Oceania, Tonga
| Name Changed | Vicariate Apostolic of Tonga Islands {Isole Tonga}, Pacific (Oceania)
| Name Changed |
| 13 Apr | Vicariate Apostolic of Taiku, Korea (South) (Zenra Holmdo (Northern Chonla))
| Territory Lost | Prefecture Apostolic of Zenshu, Korea (South)
| Erected |
| 13 Apr | Vicariate Apostolic of Taiku, Korea (South) (Zenra Nando)
| Territory Lost | Prefecture Apostolic of Kwoszu, Korea (South)
| Erected |
| 13 Apr | Vicariate Apostolic of Kasaï Superiore, Congo (Dem. Rep.) (Basongo-Brabant)
Vicariate Apostolic of Koango o Kwango, Congo (Dem. Rep.) (Niadi and Kamtseha-Loange)
| Territory Lost | Prefecture Apostolic of Ipamu, Congo (Dem. Rep.)
| Erected |
| 13 Apr | Vicariate Apostolic of Célebes, Indonesia (Makassar (Gouvernment van Geleites en Onderhoorigheden))
| Territory Lost | Prefecture Apostolic of Makassar, Indonesia
| Erected |
| 13 Apr | Vicariate Apostolic of Célebes, Indonesia
| Name Changed | Vicariate Apostolic of Manado, Indonesia
| Name Changed |
| 13 Apr | Archdiocese of Agra, India (Delhi and Punjab)
Archdiocese of Simla, India
| Territory Lost | Archdiocese of Delhi and Simla, India (and Name Change)
| Territory Added |
| 13 Apr | Prefecture Apostolic of Umtata, South Africa
| Elevated | Vicariate Apostolic of Umtata, South Africa
| Elevated |
| 13 Apr | Mission "Sui Iuris" of Bezwada, India
| Elevated | Diocese of Bezwada, India
| Elevated |
| 13 Apr | Prefecture Apostolic of Yenki [Yanji], China
| Elevated | Vicariate Apostolic of Yenki [Yanji], China
| Elevated |
| 13 Apr | Mission "Sui Iuris" of Ilan, China
| Name Changed | Mission "Sui Iuris" of Kiamusze [Jiamusi], China
| Name Changed |
| 13 Apr | Prefecture Apostolic of Bulawayo, Zimbabwe
| Elevated | Vicariate Apostolic of Bulawayo, Zimbabwe
| Elevated |
| 8 May | Archdiocese of Riga, Latvia (Courland and Semigallia)
| Territory Lost | Diocese of Liepāja, Latvia
| Erected |
| 8 May | | | Archdiocese of Riga, Latvia (became a Metropolitan)
| Elevated |
| 18 May | Prefecture Apostolic of Changtien, China
| Territory Lost | Vicariate Apostolic of Chowtsun [Zhoucun], China
| Erected |
| 18 May | Prefecture Apostolic of Kweiteh [Shangqiu], China (Kaocheng)
| Territory Lost | Vicariate Apostolic of Kaifeng [Kaifeng] (Kaifengfu), China
| Territory Added |
| 18 May | Prefecture Apostolic of Chuchow, China
| Name Changed | Prefecture Apostolic of Lishui [Lishui], China
| Name Changed |
| 18 May | Vicariate Apostolic of Togo (Sokodé, Bassari, Lama-Kara, and Sansanné-Mango)
| Territory Lost | Prefecture Apostolic of Sokodé, Togo
| Erected |
| 18 May | Vicariate Apostolic of Szepingkai [Siping], China
| Territory Lost | Prefecture Apostolic of Lintong [Lintung], China
| Erected |
| 18 May | Prefecture Apostolic of Kweiteh [Shangqiu], China
| Elevated | Vicariate Apostolic of Kweiteh [Shangqiu], China
| Elevated |
| 22 May | Diocese of Detroit, Michigan, USA (Ionia, Clinton, Allegan, Barry, Eaton, Ingham, Van Buren, Kalamazoo, Calhoun, Jackson, Berrien, Cass, St. Joseph, Branch, and Hillsdale)
| Territory Lost | Diocese of Lansing, Michigan, USA
| Erected |
| 22 May | Diocese of Detroit, Michigan, USA
| Elevated | Archdiocese of Detroit, Michigan, USA
| Elevated |
| 22 May | | | Diocese of Grand Rapids, Michigan, USA (from Cincinnati)
| Metropolitan Changed |
| 22 May | | | Diocese of Marquette, Michigan, USA (from Milwaukee)
| Metropolitan Changed |
| 1 Jun | Mission "Sui Iuris" of Cuttack, India
| Elevated | Diocese of Cuttack, India
| Elevated |
| 5 Jun | Diocese of Nocera Umbra-Gualdo Tadino, Italy (S. Helena di Annifo)
| Territory Lost | Diocese of Foligno, Italy
| Territory Added |
| 17 Jun | Diocese of Osaka, Japan (Kyoto and Shiga)
| Territory Lost | Prefecture Apostolic of Kyoto, Japan
| Erected |
| 17 Jun | Vicariate Apostolic of Hankow [Hankou], China (Suihsien, Ingshanhsien, and Anluhsien)
| Territory Lost | Prefecture Apostolic of Suixian [Suihsien], China
| Erected |