The Diocese of Pontus is a diocese of the later Roman Empire, incorporating the provinces of northern and northeastern Asia Minor up to the border with the Sassanid Empire in Armenia.
The diocese is established after the reforms of Diocletian, and its vicarius, headquartered at Amaseia, is subordinate to the Praetorian prefecture of the East.
Its military forces, facing the Sassanid threat, are commanded by the dux Ponti et Armeniae until the middle of the fifth century, and by two separate duces afterwards, until Justinian I institutes a new magister militum per Armeniam for the Armenian frontier.
Justinian's reforms also abolish the diocese in 535, and its vicar is made into the governor of Galatia I.
The results however are not satisfactory, and the diocese is reestablished in 548, continuing to function until replaced by the themata of Armeniakon and Opsikion in the later seventh century.
On the north east shore of the Black Sea, the cities Nitike, Pitiyus, and Dioscurias are part of the diocese until the seventh century.
The diocese includes twelve provinces: Bithynia, Honorias, Paphlagonia, Helenopontus, Pontus Polemoniacus, Galatia I and Galatia II (Salutaris), Cappadocia I and Cappadocia II, Armenia I, Armenia II, Armenia Maior and the autonomous Armenian principalities (Satrapiae) in the area of Sophene.
