Lough Carra (Irish: Loch Ceara) is a limestone lake (marl) of 4,000 acres (16 km²), located in the Barony of Carra, County Mayo, Republic of Ireland, approximate 8 miles (13 km) south of Castlebar. It is approximately 6 miles (9.7 km) long and varies in width from 400 yards (370 m) to one mile (1.6 km).