The River Leven is a short river in the ceremonial county of Cumbria, falling within the historic boundaries of Lancashire. It drains Windermere from its southernmost point and flows for approximately 8 miles (13 km) into the northern reaches of Morecambe Bay. The river and its estuary are the boundary between the Cartmel Peninsula and Furness Peninsula and is part of North Lonsdale, also known as Lancashire North of the Sands.
