The diocese of Pozzuoli is a Roman Catholic ecclesiastical territory in Campania, southern Italy. It is a suffragan of the archdiocese of Naples.

History

That St. Patrobas, a disciple of St. Paul, was the first bishop of Pozzuoli is a fabrication of Dositheos. The bishops St. Celsus and St. Joannes did govern the diocese before the fourth century.
Proculus, Acutius, Eutyches, and Artemas were martyrs of Pozzuoli, and St. Januarius of Benevento and his companions suffered martyrdom here.

In the 4th century the bishop of this see was Florentius, against whom Pope Damasus was compelled to seek the assistance of the emperors. Bishop St. Theodorus died in 435; Julianus was pontifical legate to the Robber Council of Ephesus in 449. The Bishop Stephanus, whom Cappelletti names at this period, should be referred to the seventh century, or later.

Other bishops were

• Gaudiosus (680);

• St. Leo (about 1030), later a hermit;

• Ludovico di Costanzo, who, with the assistance of Alfonso of Aragon, was at first a usurper of this see, but was later recognized by Pope Nicholas V;

• Carlo Borromeo (1537), a relative of the saint of the same name;

• Gian Matteo Castaldi (1542), who rebuilt the cathedral;

• Lorenzo Mongevio (1617), a Franciscan and orator, formerly Auxiliary Bishop of Salzburg and of Valencia, unjustly accused and held prisoner in Castel Sant' Angelo;

• Martin Leon y Cardenas (1619), to whom a public monument was erected.