The 2009–10 Appalachian State Mountaineers men's basketball team represented Appalachian State University in the 2009–10 NCAA Division I men's basketball season.

The Mountaineers were led by head coach Buzz Peterson in his first year leading the team in his second stint as Appalachian State's head coach after returning to the team in April of 2009.

[1] Appalachian State played their home games at the George M. Holmes Convocation Center in Boone, North Carolina, as members of the Southern Conference.

In the SoCon tournament, Appalachian State won two games to advance to the SoCon championship game, where they were defeated by South division champion Wofford.

The Mountaineers won their first two games in the CIT to advance to the tournament's semifinals, where they were eliminated by Pacific, 64–56.