The 1921 Northern Illinois State Teachers football team represented Northern Illinois State Teachers College as an independent in the 1921 college football season.
They were led by second-year head coach Paul Harrison and played their home games at Glidden Field, located on the east end of campus.
The Teachers finished the season with a 3–5 record.
Allan Newman was the team's captain.
This college football 1921 season article is a stub.