The Roman Catholic Diocese of Valence (–Die–Saint-Paul-Trois-Châteaux) (Latin: Dioecesis Valentinensis (–Diensis–Sancti Pauli Tricastinorum); French: Diocèse de Valence (–Die–Saint-Paul-Trois-Châteaux) is a diocese of the Latin Church of the Roman Catholic Church in southern France. The contemporary diocese is co-extensive with the department of Drôme.
The Cathedral of Valence was originally dedicated to Saints Cornelius and Cyprianus (Bishops of Rome and of Carthage, both mid-third century martyrs), but in 1095, during his visit to France to rouse up the aristocracy for a Crusade to liberate the Holy Land, Pope Urban II rededicated the cathedral to Saint Apollinaris, one of Valence's sixth century bishops. The Cathedral had fourteen Canons, including a Dean, a Provost, the Archdeacon, a Theologian, and the Abbot of S. Felix.In the Great Western Schism (1378–1417), the Bishops of Valence-et-Die were all appointed by and were loyal to the Popes of the Avignon Obedience.
Pope Pius VI, who had been taken prisoner and deported from Italy by troops of the French Directory, was imprisoned in the fortress of Valence. After six weeks he died there, on 29 August 1799. His body was buried in the chapel, and a month later, on First Consul Napoleon's orders, given a public funeral and buried in the town cemetery.