Femen: a territory at Slieve-na-man, extending perhaps from Cashel to Clonmel, in the southern part of the County Tipperary
Fenè: the old tribal name of the Gaels; the "King of the Fenè" is Conchobar, King of Ulster
Feorainn: a place near Ardachad, on Medb's march into Ulster
Fercerdne: chief poet of the men of Ulster
Ferdiad: (pronounced Fair-dee-ah)
Fergus macRoig: one time king of Ulster; in voluntary exile in Connacht after the treacherous putting to death of the sons of Usnech by Conchobar. He became the chief director of the Táin under Medb
Ferloga: Ailill's charioteer
Fernmag: Farney, a barony in the County Monaghan
Ferta Fingin: at Sliab Fuait
Fiachu macFiraba: one of the exiles of Ulster in the camp of Medb