The diocese of Cortona was a Roman Catholic ecclesiastical territory in central Italy, which existed from 1325 to 1986. It was immediately subject to the Holy See.
In 1986 the diocese of Cortona was united with the Diocese of Sansepolcro and the Diocese of Arezzo to form the diocese of Arezzo-Cortona-Sansepolcro. It became a suffragan (subordinate) diocese of the Metropolitan archdiocese of Florence.[1][2]