| Year: | 2009 |
| Conference: | Big Ten |
| Division: | I |
| Gender: | Men's |
| Teams: | 11 |
| Arena: | Conseco Fieldhouse |
| City: | Indianapolis, Indiana |
| Champions: | Purdue |
| Titlecount: | 1st |
| Coach: | Matt Painter |
| Coachcount: | 1st |
| Mvp: | Robbie Hummel |
| Mvpteam: | Purdue |
| Television: | BTN, ESPN, ESPN2, and CBS |
The 2009 Big Ten men's basketball tournament was played between March 12 and March 15, 2009 at Conseco Fieldhouse in Indianapolis, Indiana. It was the twelfth annual Big Ten men's basketball tournament. The championship was won by Purdue who defeated Ohio State in the championship game. As a result, Purdue received the Big Ten's automatic bid to the NCAA tournament. The win marked Purdue's first tournament championship in only their second appearance.
All Big Ten schools played in the tournament. Teams were seeded by conference record, with a tiebreaker system used to seed teams with identical conference records. Seeding for the tournament was determined at the close of the regular conference season. The top five teams received a first round bye.
| Seed | School | Conference | Tiebreaker | |
|---|---|---|---|---|
| 1 | 15–3 | |||
| 2 | Illinois | 11–7 | 2–0 vs Pur | |
| 3 | Purdue | 11–7 | 0–2 vs Ill | |
| 4 | 10–8 | 3–0 vs PSU, OSU | ||
| 5 | Ohio St | 10–8 | 1–1 vs Wisc, PSU | |
| 6 | Penn St | 10–8 | 0–3 vs Wisc, OSU | |
| 7 | Michigan | 9–9 | 2–0 vs Minn. | |
| 8 | 9–9 | 0–2 vs Mich. | ||
| 9 | Northwestern | 8–10 | ||
| 10 | Iowa | 5–13 | ||
| 11 | Indiana | 1–17 |
| Session | Game | Time | Matchup# | Score | Television | Attendance |
|---|---|---|---|---|---|---|
| Opening round – Thursday, March 12 | ||||||
| 1 | 1 | 12:00 PM |
| 66–53 | BTN | 12,174[1] |
| 2 | 2:30 PM |
| 73–45 | BTN | ||
| 3 | 5:00 PM |
| 66–51 | ESPN | ||
| Quarterfinals – Friday, March 13 | ||||||
| 2 | 4 | 12:00 PM |
| 64–56 | ESPN | 13,023[2] |
| 5 | 2:30 PM |
| 57–61 | ESPN | ||
| 3 | 6 | 6:30 PM |
| 60–50 | BTN | 14,647[3] |
| 7 | 9:00 PM |
| 79–54 | BTN | ||
| Semifinals – Saturday, March 14 | ||||||
| 4 | 8 | 1:40 PM |
| 70–82 | CBS | 15,728[4] |
| 9 | 4:05 PM |
| 56–66 | CBS | ||
| Championship Game – Sunday, March 15 | ||||||
| 5 | 10 | 3:30 PM |
| 61–65 | CBS | 12,526[5] |
| Game times in EST. #-Rankings denote tournament seeding. | ||||||
Source[6]