Pet form of John, also used as an independent given name from the 16th century onwards. In the United States it is occasionally also used as a girl's name. Famous bearers include the American country singer Johnny Cash (1932–2003) and the film actor Johnny Depp (b. 1963).
Scottish: Anglicized form of Gaelic Mac Cionaodha or Mac Cionaoith ‘son of Cionaodh’, a personal name which is probably composed of the elements cion ‘respect’, ‘affection’ + Aodh, a Gaelic personal name, originally the name of the Celtic god of fire. The personal name thus probably means ‘beloved of Aodh’.