| Year: | 2021 |
| Team: | Illinois State Redbirds |
| Sport: | football |
| Conference: | Missouri Valley Football Conference |
| Short Conf: | MVFC |
| Record: | 4–7 |
| Conf Record: | 2–6 |
| Head Coach: | Brock Spack |
| Hc Year: | 13th |
| Cooff Coach1: | C. J. Irvin |
| Cooc1 Year: | 2nd |
| Cooff Coach2: | Ghaali Muhammad-Lankford |
| Cooc2 Year: | 2nd |
| Def Coach: | Travis Niekamp |
| Dc Year: | 4th |
| Mvp: | Cole Mueller, Jacob Powell |
| Captain: | Bryce Jefferson, Zeke Vandenburgh, JT Bohlken |
| Stadium: | Hancock Stadium |
The 2021 Illinois State Redbirds football team represented Illinois State University as a member of the Missouri Valley Football Conference (MVFC) during the 2021 NCAA Division I FCS football season. Led by 13th-year head coach Brock Spack, the Redbirds compiled an overall record of 4–7 with a mark of 2–6 in conference play, placing in a three-way tie for ninth in the MVFC. Illinois State played home games at Hancock Stadium in Normal, Illinois.