Nenagh (An tAonach in Irish) is the largest town in North Tipperary, Ireland, with a population in 2002 of 6,454. It lies on the Nenagh River, which empties into Lough Derg at Dromineer, 9 km to the north. The Silvermine mountains lie to the south of the town. Nenagh is situated on the N7 National Primary Route between Limerick and Dublin.

Nenagh Castle , a potential tourist attraction, is not currently open to visitors.

Originally a market town – its full name in Irish, Aonach Urmhumhan, means "Ormonde (East Munster) Fair" – Nenagh is today a busy commercial town.

Chief amongst the town's attractions is Nenagh Castle , constructed by the FitzGerald family in the 13th Century, and one of the finest of its kind in Ireland. It is over thirty metres high, and has a base of sixteen metres. Also worth a visit is the ruined Franciscan abbey, which was built in 1212. It was in use for six hundred years, Fr. Patrick Harty, who died in 1817, being its last inhabitant.

See also

• Towns of the Republic of Ireland
• Nenagh Guardian