The 2021 Mountain West Conference Football Championship Game was a college football game played on December 4, 2021, at Dignity Health Sports Park in Carson, California.

San Diego State won the right to host the game as a result of having the better conference record between the two teams.

Utah State clinched the Mountain Division championship with a victory at New Mexico on November 26.

The Aggies finished with a conference record of 6–2 and held the head-to-head tiebreaker over Air Force thanks to their win over the Falcons on September 18.

This was the Aztecs' final game at their temporary home of Dignity Health Sports Park.