Alexander (September 19, 866 – June 6, 913), sometimes numbered Alexander III*, rules as Emperor of the Byzantine Empire in 912–913.

He is the third son of Emperor Basil I and Eudokia Ingerina.

Unlike his older brother Leo VI the Wise, his paternity is not disputed between Basil I and Michael III because he was born years after the death of Michael.

*(when numerated after Alexander Severus of the early third century, and the usurper Domitius Alexander of the early fourth century.)