2021 Illinois State Redbirds football team

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.