The Duchy of Rome (Latin: Ducatus Romanus) is a Byzantine district in the Exarchate of Ravenna.

Like other Byzantine states in Italy, it is ruled by an imperial functionary with the title dux.

These are often in conflict with the Papacy for the supreme power in Rome.Within the exarchate, the two chief districts are the country about Ravenna, where the exarch wis the center of Byzantine opposition to the Lombards, and the Duchy of Rome, which embraces the lands of Latium north of the Tiber and of Campagna to the south as far as the Garigliano.

There the pope himself is the soul of the opposition.