Donahue, Donoghue, Donohoe, Dunphy, O' Donnchadha, O' Donohoe
This name is one of the most common and one of the most important names in Ireland. Originally there were many distinct septs of the name in Counties Cork and Kerry – where Ross Castle was their fortress in Killarney. This name is from the Irish O’ Donnchadha. This is derived from the personal name Donncha – from donn meaning brown. As a result the surname would mean descendant of the brown haired or brown complexioned man.