Sentinel Mountain is an 8,245-foot-elevation (2,513 meter) summit in Glacier County, Montana, United States.

[4] Sentinel Mountain is located 1.3 miles (2.1 km) south of the Canada–United States border in the Belly River area of Glacier National Park.

Topographic relief is significant as the summit rises nearly 2,900 feet (880 meters) above the North Fork Belly River in one mile.

The mountain's toponym was officially adopted in 1929 by the United States Board on Geographic Names.

Due to its altitude, it receives precipitation all year, as snow in winter, and as thunderstorms in summer.