Slieve Gullion is a mountain in the south of County Armagh, Northern Ireland. The mountain is the heart of the Ring of Gullion and is the highest point in the county, with an elevation of 573m. At the summit is a small lake and two ancient burial cairns, one of which is the highest surviving passage grave in Ireland. Slieve Gullion plays a prominent role in the mythology and history of the area and dominates the countryside around it, offering views of as far away as Antrim, Dublin Bay and Wicklow on a clear day.
Villages around Slieve Gullion include Drumintee, Mullaghbawn, Lislea, Forkhill and Meigh. The mountain gives its name to the surrounding countryside, and is the name of an electoral area within Newry and Mourne district council.