Agents persons, peoples and institutions
- 1715–c.1788
Ó Fearghaile (Seaghan S.) See: John J. O'Farrelly
Ó Fearghusa (Seán) See: John Fergus
- 1923–1990
- Armagh, St Patrick’s College
- d. 2016
Ó Flaithbheartaigh (Ruaidhrí Óg) See: Roderic O'Flaherty
- s. xx–xxi
Ó Flannagáin (Mícheál) See: Michael O'Flanagan
Ó Floinn (Donncha) See: Donnchadh Ó Floinn [d. 1830]
- d. 1830