The Diocese of Vicenza is a Latin diocese of the Catholic Church in Italy. It is located in the region of the Veneto, and is the capital of the Province of Vicenza, approximately 60 km west of Venice, and around 45 km east of Verona. The diocese was in existence before 590. Vicenza was a suffragan of the Patriarchate of Aquileia until 1751. In 1751 it was transferred to the ecclesiastical province of Udine. In 1818, upon the dissolution of the ecclesiastical province of Udine, Vicenza was made it a suffragan of the Patriarchate of Venice.

Pope Paul II, born Pietro Barbo, was head of the Catholic Church and ruler of the Papal States from 30 August 1464 to his death. When his maternal uncle became Pope Eugene IV, Barbo switched from training to be a merchant to religious studies. His rise in the Church was relatively rapid. Elected pope in 1464, Paul amassed a great collection of art and antiquities.