List of lakes of Montana

There are at least 3223 named lakes and reservoirs in Montana. The following list contains lists of lakes and reservoirs in Montana by county.

A lake is a terrain feature (or physical feature), a body of liquid on the surface of a world that is localized to the bottom of basin (another type of landform or terrain feature; that is not global). Another definition is a body of fresh or salt water of considerable size that is surrounded by land. On Earth a body of water is considered a lake when it is inland, not part of the ocean, is larger and deeper than a pond.[1][2]

A reservoir (etymology from French réservoir a "storehouse [3]) is an artificial lake used to store water. Reservoirs may be created in river valleys by the construction of a dam or may be built by excavation in the ground or by conventional construction techniques such a brickwork or cast concrete.