Enniskillen, town, Fermanagh and Omagh district, southwestern Northern Ireland. Situated on Cethlin’s Island, it was a strategic crossing point of Lough Erne and an ancient stronghold of the Maguires of Fermanagh. Incorporated by the English king James I, it defeated a force sent by James II in 1689 and gained a reputation as a Protestant stronghold. Long a garrison town, it gave its name to the Royal Inniskilling Fusiliers and the 6th (Inniskilling) Dragoons, both famous regiments of the British army. Enniskillen functions as an agricultural market; other activities include bacon curing and hosiery manufacture. On nearby Devenish Island are the ruins of St. Mary’s Abbey, a 6th-century foundation of St. Molaise. Oscar Wilde, the late 19th-century poet and dramatist, was a student at the Royal School, founded in 1618. Pop. (2001) 13,560; (2011) 13,790.