The Diocese of Fort Wayne–South Bend is a Latin Church ecclesiastical territory, or diocese, of the Catholic Church in north-central and northeastern Indiana in the United States.

The Cathedral of the Immaculate Conception in Fort Wayne, Indiana, is the primary cathedral of the Roman Catholic Diocese of Fort Wayne-South Bend, headed by Most Rev. Kevin Carl Rhoades. The parish was established in 1836, making it the oldest in Fort Wayne. The church was erected in 1860.