| Year: | 2021 |
| Team: | Western Illinois Leathernecks |
| Sport: | football |
| Conference: | Missouri Valley Football Conference |
| Short Conf: | MVFC |
| Record: | 2–9 |
| Conf Record: | 2–6 |
| Head Coach: | Jared Elliott |
| Hc Year: | 4th |
| Off Coach: | David Rocco |
| Oc Year: | 4th |
| Def Coach: | Cam Clark |
| Dc Year: | 2nd |
| Stadium: | Hanson Field |
| Prev Year: | 2020 |
The 2021 Western Illinois Leathernecks football team represented Western Illinois University as a member of the Missouri Valley Football Conference (MVFC) for the 2021 NCAA Division I FCS football season. They were led by fourth-year head coach Jared Elliott. The Leathernecks played their home games at Hanson Field in Macomb, Illinois.