The Scottish surname Callum, also found in Ireland, is an anglicized form of the Gaelic name Mac Coluim meaning “son of Colum,” a personal name derived from Latin columba meaning “dove.”  This was the name of the 6th-century missionary known in English as St. Columba (521–597), who converted the Picts to Christianity and founded an influential monastery on the island of Iona. The name originated on Scotland’s west coast and in the Hebridies Islands.