| Mode: | Basketball |
| Year: | 2020–21 |
| Prev Year: | 2019–20 |
| Next Year: | 2021–22 |
| Team: | Saint Mary's Gaels |
| Conference: | West Coast Conference |
| Short Conf: | WCC |
| Record: | 14–10 |
| Conf Record: | 4–6 |
| Hc Year: | 20th |
| Asst Coach1: | Marcus Schroeder |
| Asst Coach2: | Justin Joyner |
| Bowl Result: | first round |
The 2020–21 Saint Mary's Gaels men's basketball team represented Saint Mary's College of California during the 2020–21 NCAA Division I men's basketball season. The team were led by head coach Randy Bennett in his 20th season at Saint Mary's. The Gaels played their home games at the University Credit Union Pavilion in Moraga, California as members of the West Coast Conference. They finished the season 14-10, 4-6 to finish in 7th place. They defeated Pepperdine in the quarterfinals in the WCC Tournament before losing in the semifinals to Gonzaga. They received an invitation to the NIT where they lost in the first round to Western Kentucky.
The Gaels finished the 2019–20 season 26–8, 11–5 in WCC play to finish in a tie for third place. They defeated Pepperdine and BYU to advance to the championship game of the WCC tournament where they lost to Gonzaga. Despite being a virtual lock to receive an at-large bid to NCAA tournament, all postseason play was cancelled amid the COVID-19 pandemic.
| Name | Number | Pos. | Height | Weight | Year | Hometown | Reason for departure | |
|---|---|---|---|---|---|---|---|---|
| 00 | G | 6'6" | 205 | RS Senior | Graduated/Signed to play professionally with Brisbane Bullets | |||
| 3 | G | 6'1" | 175 | Senior | Graduated | |||
| 5 | C | 7'1" | 250 | RS Junior | Graduate transferred to UC Riverside | |||
| Elijah Thomas | 10 | F | 6'5" | 220 | RS Junior | Graduated transferred to Cal Baptist | ||
| Dan Sheets | 15 | F | 6'5" | 205 | RS Senior | Walk-on; graduated | ||
| Kristers Zoriks | 23 | G | 6'4" | 190 | RS Sophomore | Signed to play professionally with BK VEF Rīga | ||
| 24 | F | 6'8" | 230 | RS Junior | Declare for 2020 NBA draft | |||
| Aaron Menzies | 41 | C | 7'3" | 265 | RS Senior | Graduated |
|-!colspan=9 style=| Non-conference regular season|-!colspan=9 style=| WCC regular season|-!colspan=9 style=| WCC tournament|-!colspan=12 style=| NITSource[1]
See also: 2019–20 NCAA Division I men's basketball rankings. *AP does not release post-NCAA Tournament rankings