Fitzpatrick surname meaning

Fitzpatrick looks Anglo-Norman—Fitz meaning “son of”—but in Ireland it is usually the Anglicized form of Gaelic Mac Giolla Phádraig, “son of the servant (devotee) of Saint Patrick.” That Ossory family name is cognate with Kilpatrick. Only occasionally is Fitzpatrick a genuine Norman-French patronymic “son of Patrick.” Parent’s name is high confidence either way: both the Gaelic devotee-patronymic and the rarer Norman “son of Patrick” are personal-name surnames, and the Mac Giolla Phádraig reading dominates Irish and Irish-American lines.