| Date | Event | From | To |
|---|
| 3 March 1868 | Erected | Archdiocese of Cincinnati
| Diocese of Columbus (erected) (Territory from Ohio River to the Scioto River plus the Counties of Franklin, Delaware, and Morrow)
|
| 21 October 1944 | Territory Lost | Diocese of Columbus (Carroll, Jefferson, Harrison, Guernsey, Belmont, Noble, Monroe, Morgan, Washington, Athens, Meigs, Callia, and Lawrence)
| Diocese of Steubenville (erected)
|
| 21 October 1944 | Territory Added | Archdiocese of Cincinnati (Hardin, Marion, Union, Madison, Fayette, Pickaway, Ross, Pike, and Scioto)
| Diocese of Columbus
|