Arranmore is the largest inhabited island of County Donegal, and the second largest in all of Ireland, with a population of around 500. The island is part of the Donegal Gaeltacht (Irish Speaking). The island lies off the west coast of County Donegal, Ireland.
It is also known in English as Aran Island (not to be confused with the Aran Islands off Galway Bay or the Scottish Isle of Arran). In Irish the island was traditionally called Árainn, the adjective mór (large) was added fairly recently. It was also sometimes called in Irish Árainn Uí Dhomhnaill, meaning the 'Aran of the O'Donnells'.