2023–24 Horizon League men's basketball season

The 2023–24 Horizon League men's basketball season began with practices in September 2023 and ended with the 2024 Horizon League men's basketball tournament in March 2024. This was the 44th season for Horizon League men's basketball.

This was also the final season for Horizon League member IUPUI as an institution. The Indiana University and Purdue University systems dissolved IUPUI at the end of the 2023–24 school year, replacing it with separate IU- and Purdue-affiliated institutions. The IUPUI athletic program transferred to the new IU Indianapolis (branded athletically as IU Indy), maintaining its NCAA Division I and Horizon League memberships.

Coaching changes

 * On January 31, 2023, Green Bay fired head coach Will Ryan after three seasons and a 2–19 start. Assistant coach Freddie Owens was named interim head coach. On March 14, the Phoenix hired Wyoming assistant coach Sundance Wicks as their new head coach.

Coaches
Notes:


 * Year at school includes 2023–24 season.
 * Records are prior to 2023–24 season.

Early season tournaments
The following table summarizes the multiple-team events (MTE) or early-season tournaments in which teams from the Horizon League will participate.

Horizon League tournament
The conference tournament will be played from March 5 to March 12, 2023. The first round and quarterfinals are hosted at campus sites, while the semifinals and finals are held at Indiana Farmers Coliseum in Indianapolis, Indiana. Teams are seeded by conference record, with ties broken by record between the tied teams followed by record against the regular-season champion, if necessary. The top five teams receive a bye to the quarterfinals and the bracket is re-seeded after every round.

NCAA Tournament
As the conference champion, Oakland received an automatic bid to the 2024 NCAA Division I men's basketball tournament.

College Basketball Invitational
Cleveland State accepted a bid to the 2024 College Basketball Invitational after finishing as semifinalists in the conference tournament.

CollegeInsider.com Postseason Tournament
Purdue Fort Wayne accepted a bid to the 2024 CollegeInsider.com Postseason Tournament after finishing as quarterfinalists in the conference tournament.

Midseason watchlists
Below is a table of notable midseason watch lists.