| Mode: | Basketball |
| Year: | 2020–21 |
| Team: | Western Illinois Leathernecks |
| Conference: | Summit League |
| Short Conf: | The Summit |
| Record: | 7–15 |
| Conf Record: | 5–9 |
| Hc Year: | 1st |
| Assoc Coach: | Chad Boudreau |
| Asst Coach1: | Kyle Heikkinen |
| Asst Coach2: | Nick Irvin |
The 2020–21 Western Illinois Leathernecks men's basketball team represented Western Illinois University in the 2020–21 NCAA Division I men's basketball season. The Leathernecks, led by first-year head coach Rob Jeter, played their home games at Western Hall in Macomb, Illinois, as members of the Summit League.
The Leathernecks finished the 2019–20 season 5–21, 2–14 in Summit League play to finish in last place. They failed to qualify for the Summit League tournament.
On March 3, 2020, the school announced that head coach Billy Wright's contract would not be renewed.[1] He finished at Western Illinois with a six-year record of 53–115. On March 30, the school announced former Milwaukee head coach Rob Jeter would be hired as the new head coach.[2]
|-!colspan=12 style=| Non-conference regular season|-!colspan=9 style=| Summit League regular season|-!colspan=9 style=| Summit League tournament|-Source[3]