The Battle of Portlester took place on 7 August 1643 near the town of Ballivor, Leinster in Ireland as part of the Irish Confederate Wars. It was fought between the Ulster Army under Owen O'Neill and a largely Protestant government force from Dublin under Lord Moore, with both sides proclaiming their basic loyalty to Charles I. The battle consisted primarily of an exchange of artillery fire in which Moore was killed and his army driven off, giving the Confederates victory.