The Diocese of Padua is a Latin diocese of the Catholic Church in Veneto, northern Italy. It was erected in the 3rd century. The diocese of Padua was originally a suffragan (subordinate) of the Patriarchate of Aquileia. When the Patriarchate was suppressed permanently in 1752, it became a suffragan of the Archdiocese of Udine. In 1818, when the dioceses of northern Italy were reorganized by Pope Pius VII, it became a suffragan of the Patriarchate of Venice, and remains so today.

The Patriarchate of Venice, also sometimes called the Archdiocese of Venice, is a Latin Church ecclesiastical territory or patriarchal archdiocese of the Catholic Church in Venice, Italy. In 1451 the Patriarchate of Grado was merged with the Bishopric of Castello and Venice to form the Archdiocese of Venice.