Mansur ibn Sarjun was a Byzantine fiscal official or governor of Damascus of local Syrian origin under emperors Maurice (r. 582–602) and Heraclius (r. 610–641), as well as during the Persian occupation of Damascus in 614–628. He surrendered the city to the besieging Arab Muslims in 635, having first secured the safe conduct of the local inhabitants. For his role in the surrender, he was maligned in Christian circles. Mansur's family remained prominent under Muslim rule, with his son Sarjun serving as a high-ranking official in Syria under the early Umayyad caliphs and his grandson John of Damascus attaining prominence as one of the major Christian thinkers of his time.