Alexander MacDonnell, 3rd Earl of Antrim PC (Ire) (1615–1699) was a Catholic peer and military commander in Ireland. He fought together with his brother Randal on the losing side in the Irish Confederate Wars (1641–1653); and then, having succeeded his brother as the 3rd Earl of Antrim in 1683, fought in the Williamite War (1688–1691), on the losing side again. Twice he forfeited his lands and twice he regained them. However, he may be known best for having been shut out of Derry by the apprentice boys in an episode preceding the Siege of Derry.
