1991 Atlantic 10 men's basketball tournament

The 1991 Atlantic 10 men's basketball tournament was played from March 2 to March 4, 1991, and March 7, 1991, at the Palestra in Philadelphia, Pennsylvania, except for the final that was played at Rec Hall in University Park, Pennsylvania. The winner was named champion of the Atlantic 10 Conference and received an automatic bid to the 1991 NCAA Men's Division I Basketball Tournament. Penn State University won the tournament. Temple and Rutgers also received bids to the NCAA Tournament. Freddie Barnes of Penn State was named the tournament's Most Outstanding Player. The top six teams in the conference received first-round byes.

Penn State departed the Atlantic 10 following this season. The Nittany Lions played an independent schedule in 1991-92, then joined the Big Ten on July 1, 1992.

Bracket
* - Overtime