Fathadh mac Aonghus (fl. 10th–11th centuries) was an Irish nobleman.
Pádraig Ó Fathaigh (1879–1976) was a member of the Gaelic League and an Intelligence Officer of the Irish Republican Army.
A surname, family name, or last name is the portion of a personal name that indicates a person's family (or tribe or community, depending on the culture).
Tadhg an tSleibhe Ó Fathaigh, Irish Chief of the Name, fl.