Holy Cross Abbey (Mainistir na Croise Naofa) was a Cistercian monastery in Holycross near Thurles, County Tipperary, Ireland, situated on the River Suir.

The Annals of the Kingdom of Ireland records a 1601 pilgrimage to Holy Cross Abbey by Irish clan chief Hugh Roe O'Donnell, Lord of Tyrconnell.

By that period, the Abbey had become a rallying point for resistance to the religious persecution of the Catholic Church in Ireland and for the rising of the Irish clans as part of the ongoing Nine Years War.

From there, O'Donnell sent an expedition to Ardfert, to win a quick victory and successfully recover the territory of his ally, Thomas Fitzmaurice, 18th Baron Kerry, who had lost it and his 9-year-old son to Sir Charles Wilmot.

Special legislation in the Dáil for the founding's 500th anniversary, 21 January 1969, enabled Holy Cross Abbey to be restored as a place of Catholic worship, exceptionally for a national monument.