The Moy (in Irish Abhainn Na Muaidhe ) is a river of Ireland which takes its source in mountains OX in the Comté of Sligo. In most of its course Moy runs out towards south-west before entering the Comté of Mayo, passing beside the town of Swinford then to turn towards north, to cross the town of Ballina and throwing in Bay of Killala its mouth on the Atlantic Ocean

The river is one of saumoneuses of Europe. Many fish breedings there are also found. The valley of Moy is very attended by the tourists who come to see the many churches and abbeys.