Camp Three is a rural census-designated place (CDP) in Musselshell County, Montana, United States.

According to the U.S. Census Bureau, the Camp Three CDP has a total area of 4.45 square miles (11.5 km2), all land.

The racial makeup of the CDP was 95.65% White, 1.45% Native American, 1.45% Asian, and 1.45% from two or more races.

45.5% of all households were made up of individuals, and 20.8% had someone living alone who was 65 years of age or older.

There were 11.9% of families and 20.3% of the population living below the poverty line, including 53.8% of under eighteens and 4.7% of those over 64.