The Diocese of Fort Wayne–South Bend encompasses 14 Indiana counties: Adams, Allen, DeKalb, Elkhart, Huntington, Kosciusko, LaGrange, Marshall, Noble, Steuben, St. Joseph, Wabash, Wells, and Whitley.

Several years after the American Revolution in 1789, Pope Pius VI erected the Diocese of Baltimore, covering the entire United States.

In 1808, Pope Pius VII erected the Diocese of Bardstown, with jurisdiction over the Indiana Territory and other areas in the Midwest.

[2] In 1834, Pope Gregory XVI erected the Diocese of Vincennes, encompassing all of Indiana and the eastern third of Illinois.

St. Patrick's Roman Catholic Church in Lagro was first constructed in 1838, as was St. Vincent de Paul in Logansport and St. Charles Borromeo in Peru.

In 1863, Luers held a synod of priests at the University of Notre Dame in which he established the laws and constitution for the diocese.

[6] He also founded the Catholic Clerical Benevolent Association of the Diocese of Fort Wayne for the support of elderly and sick priests.

In 1872, Pope Pius IX appointed Joseph Dwenger as the second bishop of the Diocese of Fort Wayne.

The next bishop of Fort Wayne was Herman Alerding of the Diocese of Vincennes, named by Leo XIII in 1900.

John F. Noll was appointed the fifth bishop of the Diocese of Fort Wayne by Pope Pius XI in 1925.

After Noll died in 1956, Pope Pius XII named Auxiliary Bishop Leo Pursley as his replacement.

In his letter, Pursley warned Marshall that Paquette had been accused of molesting boys and should, if accepted in Vermont, be kept away from children.

[11] In September 2018, Bishop Rhoades released a list of 18 priests and deacons who previously served the diocese and were credibly accused of sexually abusing minors.

[14] Mother Theodore Guérin, founder of the Sisters of Providence of Saint Mary-of-the-Woods is considered the patron of education in the Diocese of Fort Wayne-South Bend.