Sebastokrator, was a senior court title in the late Byzantine Empire. It was also used by other rulers whose states bordered the Empire or were within its sphere of influence. The word is a compound of sebastós and krátōr. The wife of a Sebastokrator was named sebastokratorissa in Greek, sevastokratitsa (севастократица) in Bulgarian and sebastokratorica in Serbian.

Sebastos was an honorific used by the ancient Greeks to render the Roman imperial title of Augustus. The female form of the title was sebaste (σεβαστή). It was revived as an honorific in the 11th-century Byzantine Empire, and came to form the basis of a new system of court titles. From the Komnenian period onwards, the Byzantine hierarchy included the title sebastos and variants derived from it, like sebastokrator, protosebastos, panhypersebastos, and sebastohypertatos.