Baithéne mac Brénaind was a 6th-century Irish monk and a close companion of Saint Columba. As a member of the Cenél Conaill, he accompanied Columba to Scotland around 563 and eventually became the first successor to serve as the abbot of Iona Abbey. He is remembered for his deep faith and his leadership over monastic sites, including a house for penitents on the island of Tiree. He died around 598, having served as a trusted disciple and leader within the Columban monastic tradition.