1989 American South Conference men's basketball tournament

The 1989 American South Conference men's basketball tournament was held March 4–6 at the Cajundome at University of Southwestern Louisiana in Lafayette, Louisiana.

Louisiana Tech defeated in the championship game, 84–62, to take home their second American South men's basketball tournament title.

Louisiana Tech received an at-large invitation to the 1989 NCAA Tournament as the #9 seed in the Southeast region because the American South was not eligible for an automatic bid at the time. The Bulldogs defeated La Salle 83–74 before losing to #1 seed Oklahoma 124–81.

Format
All six of the conference's founding members participated in the tournament field. They were seeded based on regular season conference records. The top two teams were given byes into the semifinals while the bottom four teams were placed and paired into the initial quarterfinal round.

All games were played at the Cajundome in Lafayette, Louisiana.