| Year: | 2021 |
| Conference: | Big West Conference |
| Division: | I |
| Gender: | Men's |
| Teams: | 10 |
| Arena: | Michelob Ultra Arena |
| City: | Paradise, Nevada |
| Champions: | UC Santa Barbara |
| Titlecount: | 4th |
| Coach: | Joe Pasternack |
| Coachcount: | 1st |
| Mvp: | JaQuori McLaughlin |
| Mvpteam: | UC Santa Barbara |
| Television: | ESPN3 ESPNU ESPN2 |
The 2021 Big West Conference men's basketball tournament was the postseason men's basketball tournament for the Big West Conference of the 2020-21 NCAA Division I men's basketball season. It was held from March 9–13, 2021 at the Michelob Ultra Arena in Paradise, Nevada. The winner received the conference's automatic bid to the 2021 NCAA tournament.[1]
Of the 11 conference teams, 10 were eligible for the tournament. UC San Diego was ineligible for this year's tournament, as they were in the first year of the four-year transition required for teams transferring to Division I from Division II. Teams were seeded by record within the conference, with a tiebreaker system to seed teams with identical conference records. Unlike previous years, reseeding teams after the quarterfinals did not take place for this year's tournament.
| Seed | School | Conference | Tiebreaker | |
|---|---|---|---|---|
| 1 | align=left | 13–3 | ||
| 2 | 10–4 | |||
| 3 | 8–4 | |||
| 4 | 6–4 | |||
| 5 | 9–7 | |||
| 6 | 9–9 | |||
| 7 | 5–7 | |||
| 8 | 5–9 | |||
| 9 | 4–8 | |||
| 10 | 1–15 |
| Game | Time [2] | Matchup | Score | Television | |
|---|---|---|---|---|---|
| First round – Tuesday, March 9 | |||||
| 1 | 2:30 pm | No. 8 CSUN vs. No. 9 Long Beach State | 63–85 | ESPN3 | |
| 2 | 5:00 pm | No. 7 CSU Fullerton vs. No. 10 Cal Poly | 82–87 | ||
| Quarterfinals – Thursday, March 11 | |||||
| 3 | 11:00 am | No. 1 UC Santa Barbara vs. No. 9 Long Beach State | 95–87 | ESPN3 | |
| 4 | 2:00 pm | No. 4 UC Davis vs. No. 5 CSU Bakersfield | 58–56 | ||
| 5 | 5:00 pm | No. 2 UC Irvine vs. No. 10 Cal Poly | 58–51 | ||
| 6 | 8:00 pm | No. 3 UC Riverside vs. No. 6 Hawaii | 62–52 | ||
| Semifinals – Friday, March 12 | |||||
| 7 | 6:00 pm | No. 1 UC Santa Barbara vs. No. 4 UC Davis | 71–55 | ESPN3 | |
| 8 | 9:00 pm | No. 2 UC Irvine vs. No. 3 UC Riverside | 78–61 | ESPNU | |
| Final – Saturday, March 13 | |||||
| 9 | 8:30 pm | No. 1 UC Santa Barbara vs. No. 2 UC Irvine | 79–63 | ESPN2 | |
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