Long Lake is a thirteen mile lake between Naples, Maine and Harrison, Maine.It is connected to Brandy Pond through the Chute River. Long Lake was created by receding glaciers, and has many coves and rocks. Each November, Long Lake is drained by about 3 feet so that melting snow does not cause a flood in the Spring.

Long Lake was a federal electoral district in Saskatchewan, Canada, that was represented in the Canadian House of Commons from 1925 to 1935.

In J. R. R. Tolkien's fictional world of Middle-earth, the Long Lake is a lake situated at the confluence of the Forest River and the northern reaches of the Celduin south of the Lonely Mountain.