Castle Mountain () is in the Beartooth Mountains in the U.S. state of Montana, about east-northeast of Cooke City. It is located in the Gallatin National Forest and Custer National Forest, just outside the northern boundary of Yellowstone National Park in the AbsarokaâÂÂBeartooth Wilderness.
The peak is the third tallest in the Beartooth Mountains, and the highest point in Carbon County, Montana.