The 2009–10 Maryland Terrapins men's basketball team represented the University of Maryland in the 2009–10 college basketball season as a member of the Atlantic Coast Conference (ACC). Gary Williams was in his 21st year as the team's head coach. The Terrapins finished the season 24–9, 13–3 in ACC play, to claim a share of the regular-season championship with Duke. They lost in the quarterfinals of the 2010 ACC men's basketball tournament to Georgia Tech. They received an at-large bid to the 2010 NCAA Division I men's basketball tournament, earning a 4-seed in the Midwest Region. They defeated 13-seed Houston in the first round before losing to 5-seed and AP #13 Michigan State in the second round.