Ó Fathaigh

O'Fahey (Ó Fathaigh) is an anglicised form of Ó Fathaigh. The patronym means "descendant of Fathaigh", whose name means "base" or "foundation". Cormac Ó Fathaigh is the first recorded bearer with the surname and is the purported ancestor of any Ó Fathaigh descendants. The surname largely became Fahey, with many variations.

Notable descendants

 * Pádraig Ó Fathaigh (1879–1976), Irish Republican Army intelligence officer