The 2020–21 Mount St. Mary's Mountaineers men's basketball team represented Mount St. Mary's University during the 2020–21 NCAA Division I men's basketball season.

The Mountaineers were led by third-year head coach Dan Engelstad, and played their home games at Knott Arena in Emmitsburg, Maryland as members of the Northeast Conference.

They defeated Wagner and Bryant to be champions of the NEC tournament.

They received the conference's automatic bid to the NCAA tournament where they lost in the First Four to Texas Southern.

They lost in the quarterfinals of the NEC tournament to Sacred Heart.