Roman Catholic Suburbicarian Diocese of Ostia

The Roman Catholic Suburbicarian Diocese of Ostia is an ecclesiastical territory located within the Metropolitan City of Rome in Italy.

The incumbent Bishop is Cardinal Giovanni Battista Re.

Since 1150, its bishop has been the Dean of the College of Cardinals.

[1] Its Cathedral is Basilica di Sant'Aurea.

In 1962, the Diocese of Ostia was brought under the direct administration of the Diocese of Rome.