Murphy (Ó Murchadha or Mac Murchadha) is the most common surname in Ireland.
It arose independently in several parts of Ireland: Tyrone, Sligo, and Wexford.
Today it is found in Wexford, Carlow, Cork, Kerry. The Ulster Murphys are strong in Armagh and the surname is widepread in Ulster. A more modern spelling is Ó Murchú (pronounced ó murrakhoo).