Thunder Mountain is an 11,441-foot (3,487-metre) summit in Carbon County, Montana, United States.

[1] It is set within the Absaroka–Beartooth Wilderness on land managed by Custer-Gallatin National Forest.

[2] Precipitation runoff from the mountain's slopes drains into Lake Fork → Rock Creek → Clarks Fork Yellowstone River → Yellowstone River.

Topographic relief is significant as the summit rises 2,600 feet (792 meters) above Lake Fork in 0.75 miles (1.21 km).

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