The Rocky Mountain Athletic Conference (RMAC), commonly known as the Rocky Mountain Conference (RMC) from approximately 1910 through the late 1960s, is a college athletic conference affiliated with the National Collegiate Athletic Association (NCAA) at the Division II level, which operates in the western United States.

Founded in 1909, the Rocky Mountain Athletic Conference is the fifth oldest active college athletic conference in the United States, the oldest in NCAA Division II, and the sixth to be founded after the Michigan Intercollegiate Athletic Association, the Big Ten Conference, the Southern Intercollegiate Athletic Association, the Ohio Athletic Conference, and the Missouri Valley Conference.

The presidents assumed control of the league from the faculty in 1967 and changed the name to Rocky Mountain Athletic Conference.

The Colorado Athletic Conference dissolved in 1996, with the RMAC absorbing the remaining CAC teams.

Of those schools, only Colorado Mines has been with the conference every year since it was founded in 1909.