The 2021 Saint John's Johnnies football team represented Saint John's University as a member of the Minnesota Intercollegiate Athletic Conference (MIAC) during the 2021 NCAA Division III football season.
Led by eighth-year head coach Gary Fasching, the Johnnies compiled an overall record of 11–1 with a mark of 8–0 in conference play.
As MIAC champion, Saint John's received and automatic bid to the NCAA Division III Football Championship playoffs, where the defeated Lake Forest in the first round before losing to Linfield in the second round.
The Johnnies played home games at Clemens Stadium in Collegeville, Minnesota.
This college football 2020s season article is a stub.