The 2009 Horizon League men's basketball tournament was held at the end of the 2008–2009 regular season. The better seed hosted each first round match. The second and third rounds were played at Hinkle Fieldhouse in Indianapolis. The championship game was played at the home court of the highest remaining seed, also Hinkle Fieldhouse, the home court of the Butler men's basketball team.

Regular season standings

tiebreakers having failed to distinguish the two teams.

Bracket

First round games at campus sites of lower-numbered seeds Second round and semifinals hosted by Butler. Championship hosted by lower-numbered remaining seed

All-Tournament Team