The 2011 NCAA Men's Division I Basketball Tournament is a single-elimination tournament involving 68 teams to determine the national champion of the 2010–11 NCAA Division I men's basketball season. The 73rd edition of the NCAA Tournament began on March 15, 2011, and will conclude with the championship game on April 4 at Reliant Stadium in Houston, Texas. This tournament marked the introduction of the "First Four" round and an expansion of the field of participants from 65 teams to 68.

This tournament is notable for its large number of upsets. In the Southwest region, Florida State (a 10 seed), VCU (11) and Richmond (12) made the regional seminfinals. This marked the first time in the history of the tournament that a region was represented by three double-digit seeds in the Sweet Sixteen. The tournament will feature the first Final Four to not have one of the top two seeds from any of the four regions. VCU tied 11th-seeded LSU in 1986 and George Mason in 2006 as the lowest seeds ever to reach the Final Four. The semifinal game between VCU and Butler, an 8 seed, will have the greatest seed number total of any Final Four matchup in history (19, surpassing the previous mark of 14 set in 1980 and matched in 2006). The Final Four as a whole will similarly have the greatest seed number total ever (26, surpassing the previous mark of 22 set in 2000). The championship game will be only the third final in tournament history to feature a team seeded 8 or lower; UCLA, an 8 seed, appeared in the 1980 final, and Villanova, another 8 seed, won the 1985 tournament.