The Dominate, also known as the late Roman Empire, is the name sometimes given to the "despotic" later phase of imperial government in the ancient Roman Empire. It followed the earlier period known as the "Principate". Until the empire was reunited in 313, this phase is more often called the Tetrarchy.

It may begin with the commencement of the reign of Diocletian in AD 284, following the Third Century Crisis of AD 235–284, and to end in the west with the fall of the Western Roman Empire in AD 476, while in the east its end is disputed, with the majority of opinions placing it around the transition between the Justinian and Heraclian dynasties, between the years 565 and 641. In form, the Dominate is considered to have been more authoritarian, less collegial and more bureaucratic than the Principate from which it emerged.