Marcus Eremita, Mark the Ascetic or Marcus the Ascetic was a Christian theologian, saint, and ascetic writer of the fifth century AD.

Mark is rather an ascetic than a dogmatic writer. He is content to accept dogmas from the Church; his interest is in the spiritual life as it should be led by monks. He is practical rather than mystic, belongs to the Antiochene School and shows himself to be a disciple of John Chrysostom.