Byzantine Armenia, sometimes known as Western Armenia, is the name given to the parts of Kingdom of Armenia that became part of the Byzantine Empire. The size of the territory varied over time, depending on the degree of control the Byzantines had over Armenia.

The Byzantine and Sassanid Empires divided Armenia in 387 and in 428. Western Armenia fell under Byzantine rule, and Eastern Armenia fell under Sassanid control. Even after the establishment of the Bagratid Armenian Kingdom, parts of historic Armenia and Armenian-inhabited areas were still under Byzantine rule.