Art mac Cuinn
- Unmarried: Achtan
- Died: Abt 195, Maigh Mucruimhe near Athenry, Galway, Ireland
- Buried: Abt 195, Tullach Art, Galway, Ireland
The Battle of Maigh Mucruimhe, in which the legendary High King of Ireland, Art mac Cuinn, fell, was fought on a plain (Magh) to the immediate west of where the town of Athenry, County Galway, now stands. It is dated to AD 195 by the Annals of the Four Masters and 173 according to Seathrún Céitinn's chronology. It is also the name of a narrative of the Historical Cycle of Irish mythology.
Lugaid mac Con of the Érainn of Munster had been forced into exile in Britain following a battle with his foster-brother Éogan, grandson of Mug Nuadat, the king of Munster. He returned with Beinne Brit, son of the king of Britain, at the head of an army of Britons and other foreigners, and took the High Kingship by defeating both Art and Éogan at Magh Mucruimhe. Art's celebrated son Cormac was conceived the night before the battle.
A leacht or memorial stone was erected either at the spot where Art was killed or where his body was interred at a place called Tullach Art, the "hill of Art".
Mucruimhe is translated as "reckoning of the swine", which can be taken to indicate that a market may have being held upon it. Indeed well into the late medieval era a market was indeed held just outside the town walls, west of the Swan Gate. A plinth in a field is all that remains of a stone cross where the market was held.
Art had a relationship with Achtan.