Mac Giolla Ruaidh
Mac GIOLLA RUAIDH—IV—M'Gillarowe, M'Gillaroe, M'Gillaroye, M'Killeroe, M'Killroy, MacGillroy, MacGilroy, MacIlroy, MacElroy, MacAlroy, MacLeroy, Gilroy, Kilroy, Ilroy, Roy, and, by 'translation,' King; 'son of Giolla ruadh' (red youth); the name of a Fermanagh family, the head of which resided at Ballymackilroy, in the parish of Aghalurchur, near Lough Erne. In the 16th century, it was common in Down, Cavan, Roscommon and Offaly. It is sometimes erroneously translated King.
Alphabetical Index to Irish Surnames