Boyle, a market town of Co. Roscommon, Ireland, in the north parliamentary division, on the Sligo line of the Midland Great Western railway, 106¼ m. N.W. by W. from Dublin and 28 m. S. by E. from Sligo. Pop. (1901) 2477. It is beautifully situated on both banks of the river Boyle, an affluent of the Shannon, between Loughs Gara and Key. Three bridges connect the two parts of the town. There is considerable trade in agricultural produce. To the north of the town stand the extensive ruins of a Cistercian abbey founded in 1161, including remains of a cruciform church, with a fine west front, and Norman and Transitional arcades with carving of very beautiful detail. The offices of the monastery are well preserved, and an interesting feature is seen in the names carved on the door of the lodge, attributed in Cromwell’s soldier, who occupied the buildings. Neighbouring antiquities are Asselyn church near Lough Key, and a large cromlech by the road towards Lough Gara. Boyle was incorporated by James I., and returned two members to the Irish parliament.