The Roman Catholic Diocese of Knoxville () is a Roman Catholic diocese in Tennessee. It was founded on May 27, 1988 from the eastern counties of the Diocese of Nashville. This diocese covers most of East Tennessee; in addition to the see city of Knoxville, it includes Chattanooga and Johnson City. The Mother Church is the Cathedral of the Most Sacred Heart of Jesus, located on Northshore Drive in Knoxville. The two oldest churches are Saints Peter and Paul Basilica Parish of Chattanooga and Church of the Immaculate Conception Parish of Knoxville, both founded in 1852.