Saint Mary Peak is a 9,351-foot elevation (2,850 m) mountain summit located in Ravalli County, Montana.

Saint Mary Peak is located in the Bitterroot Range, which is a subset of the Rocky Mountains.

It is situated eight miles west of Stevensville in the Selway–Bitterroot Wilderness, on land managed by Bitterroot National Forest.

Topographic relief is significant as the summit rises over 5,000 feet (1,500 meters) above Big Creek in three miles.

This landform's toponym has been officially adopted by the United States Board on Geographic Names.