The diocese included the larger part of Lippe, Waldeck, and nearly half of the County of Ravensberg.

Through the Prussian Concordate, it was promoted to an archdiocese in 1930, heading the new Middle German Ecclesiastical Province; at the same time, Paderborn lost its districts around Erfurt and Heiligenstadt to the Diocese of Fulda, and two small areas to the Archdiocese of Cologne.

When the Diocese of Essen was created in 1958, Paderborn lost a significant portion of its district to it.

In 1994 Paderborn lost the part of its district located in the former East Germany to its newly created suffragan Diocese of Magdeburg.

In the 1990s, the conflict between the Archdiocese and renegade priest Eugen Drewermann made headlines.