| Year: | 1990 |
| Conference: | Midwestern Collegiate Conference |
| Division: | I |
| Gender: | Men's |
| Teams: | 8 |
| Arena: | UD Arena |
| City: | Dayton, Ohio |
| Champions: | Dayton |
| Titlecount: | 1st |
| Coach: | Jim O'Brien |
| Coachcount: | 1st |
| Mvp: | Negele Knight |
| Mvpteam: | Dayton |
The 1990 Midwestern Collegiate Conference men's basketball tournament (now known as the Horizon League men's basketball tournament) was held March 8–10 at UD Arena in Dayton, Ohio.[1]
Dayton defeated Xavier in the championship game, 85–78. The win, on Dayton's home court, denied the Musketeers a fifth consecutive MCC/Horizon League men's basketball tournament title. It was Dayton's first MCC/Horizon League tourney title.
The Flyers received an automatic bid to the 1990 NCAA tournament as the #12 seed in the Midwest region. Xavier, the regular season conference champions, received an at-large bid as the #6 seed in the Midwest region.
All eight conference members participated in the tournament and were seeded based on regular season conference records.