Born Travers Hegarty in Berwick upon Tweed, he became an actor before emigrating to America in the 1920s. From 1933 he became noted for his kindly grandfatherly demeanour. He appeared in such films as The Invisible Man (1933), High Sierra (1941), Mrs Miniver (1942) for which he was nominated for an Oscar as best supporting actor, and Random Harvest (1942).
His most famous role, however, was as Clarence the rather fuddled angel in Frank Capra's It's a Wonderful Life (1946)