Lough Oughter is a lake, or complex of lakes, in County Cavan covering more than 8,900 hectares. The complex of lakes lies on the River Erne, and forms the southern part of the Lough Erne complex. The lakes are bounded roughly by Belturbet in the north, Cavan town to the east, Crossdoney to the south and Killeshandra to the west.

County Cavan is a county in Ireland. It is in the province of Ulster and is part of the Northern and Western Region. It is named after the town of Cavan and is based on the historic Gaelic territory of East Breffny (Bréifne). Cavan County Council is the local authority for the county, which had a population of 81,704 at the 2022 census.