Nenagh ( or , locally ; or simply An tAonach) is the county town of North Tipperary in Ireland. In 2011 it had a recorded population of 7,995. It is a civil parish in the historical barony of Ormond Lower. It is also an Ecclesiastical parish in the Roman Catholic Diocese of Killaloe.
Nenagh was originally a market town, and its name in Irish means "The Fair of Ormond" – a reference to the Ormond (East Munster) Fair, of which it was the site. Nenagh is today a busy commercial town and is governed by Nenagh Town council.