McCartney (a variant of Macartney or MacCartney)'s a surname that originated in Ireland. It isn't to be confused with McCarthy, which has different origins. The McCartneys are a branch of the great family of McCarthy Mor of Munster, who were Kings of Cork and Princes of Desmond. The fifth son of Cormac Fionn d.1248 was Donogh Cartnach who's the ancestor of the McCartneys. Donough Cartnach left 2 sons, the eldest Donal joined Edward Bruce (King of Ireland), . For serving under Robert the Bruce's… (More on Mccartney)