2005 Big Ten Men's Basketball Tournament
The 2005 Big Ten Conference Men's Basketball Tournament was played between March 9 and March 12, 2005 at the United Center in Chicago, Illinois. This was the eighth annual Big Ten Men's Basketball Tournament. The championship was won by Illinois who defeated Wisconsin in the championship game. As a result, Illinois received the Big Ten's automatic bid to the NCAA Tournament. The win marked the second tournament championship for Illinois in their fifth championship game appearance.Seeds
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 |
| 1 | Illinois | 15–1 |
| 2 | Michigan State | 13–3 |
| 3 | Wisconsin | 11–5 |
| 4 | Indiana | 10–6 |
| 5 | Minnesota | 10–6 |
| 6 | Ohio State | 8–8 |
| 7 | Iowa | 7–9 |
| 8 | Northwestern | 6–10 |
| 9 | Michigan | 4–12 |
| 10 | Purdue | 3–13 |
| 11 | Penn State | 1–15 |
Bracket
