The 2020 Western Illinois Leathernecks football team represented Western Illinois University as member of the Missouri Valley Football Conference (MVFC) during the 2020–21 NCAA Division I FCS football season. Led by third-year head coach Jared Elliott, the Leathernecks compiled an overall record of 1–5 with an identical mark in conference play, placing ninth in the MVFC. Western Illinois played home games at Hanson Field in Macomb, Illinois.