The 1991 Patriot League men's basketball tournament was played at Hart Center in Worcester, Massachusetts after the conclusion of the 1990–1991 regular season.
Top seed Fordham defeated #3 seed Holy Cross, 84–81 (OT) in the championship game, to win the first Patriot League Tournament.
The Rams were then defeated by Saint Francis (PA) in one of three play-in games to the 1991 NCAA tournament.
All seven league members participated in the tournament, with teams seeded according to regular season conference record.
Regular-season champion Fordham received a bye to the semifinal round, with the other six teams playing a quarterfinal round.