Fan Mountain, 'el. 10,312 feet is a prominent peak in the Madison Range in Madison County, Montana in the Beaverhead National Forest. The peak is located along the western face of the Madison Range at the northern end of the range. It is due east of Ennis Lake and its prominence and isolation makes it easy to distinguish it from Ennis in the Madison River valley.

Fan Mountain-Because the small gullies and ridges of the alluvial fan on the Madison valley side of this mountain look like the rays of a fan, the name becomes obvious.
The previous variant name was Cedar Mountain, but the name was changed in 1932 to prevent confusion with the nearby Cedar Mountain at the head of Cedar Creek.