The diocese of Cortona was a Roman Catholic ecclesiastical territory in central Italy, which existed from 1325 to 1986. In that year it was combined with the Diocese of Sansepolcro and the Diocese of Arezzo to form the diocese of Arezzo-Cortona-Sansepolcro. It was immediately subject to the Holy See.
Ancient Cortona was one of the twelve cities of Etruria. Later it was destroyed by the Lombards but was soon rebuilt. From that time until 1325 it belonged to the Diocese of Arezzo. In that year, at the request of Guglielmo Casali, Pope John XXII raised Cortona to episcopal rank, as a reward for the fidelity of its Guelph populace, Arezzo remaining Ghibelline. The current Cathedral of Cortona became the diocesan seat only in 1507.
This article incorporates text from a publication now in the public domain: Herbermann, Charles, ed. (1913). "". Catholic Encyclopedia. New York: Robert Appleton.