The 2021 Stephen F. Austin Lumberjacks football team represented Stephen F. Austin State University in the 2021 NCAA Division I FCS football season as a member of the Western Athletic Conference (WAC).

The Lumberjacks were led by third-year head coach Colby Carthel and played their home games at Homer Bryce Stadium.

The Challenge included the four fully qualified Division I (FCS) members of the WAC (Abilene Christian, Lamar, Sam Houston, and Stephen F. Austin) and Central Arkansas, Eastern Kentucky, and Jacksonville State of the ASUN Conference.

The winner of the challenge received an auto-bid to the NCAA Division I FCS football playoffs.

[1] The Western Athletic Conference coaches released their preseason poll on July 27, 2021.