Montes Haemus is a mountain range that forms the southwestern edge of the Mare Serenitatis basin on the Moon.

It forms a less prominent mirror image of the Montes Apenninus range to the west, and curves up to nearly join at the northern end.

But he assigned this name (in the form Mons Æmus) to another feature – remains of the rim of crater Alexander, located on the other side of Mare Serenitatis.

The eastern end of the range forms the western terminus of a rille system designated Rimae Plinius.

Where the mountain range curves up to the northwest, the cup-shaped crater Sulpicius Gallus lies nearby on the lunar mare.