What is the largest lake in the United Kingdom?

Lough Neagh is the largest lake in the United Kingdom by surface area.

Located in Northern Ireland, Lough Neagh covers about 383 square kilometres, or roughly 148 square miles. It is also the largest lake in the British Isles and on the island of Ireland. The lough lies about 20 miles west of Belfast and stretches approximately 19 miles from end to end.

The lake is broad but relatively shallow. Its average depth is about 30 feet, while its deepest point is roughly 80 feet. The Upper River Bann and several other rivers feed it, and water leaves through the Lower Bann, eventually reaching the Atlantic Ocean. Lough Neagh’s catchment drains a substantial portion of Northern Ireland, and the lake supplies a significant share of the region’s drinking water.

Loch Lomond and Loch Ness are frequent wrong answers because they are famous Scottish lochs. Loch Ness is the largest UK lake by volume, while Lough Neagh is largest by surface area—the usual meaning of “largest lake” in this question.