The 1991 San Diego State Aztecs football team represented San Diego State University during the 1991 NCAA Division I-A football season as a member of the Western Athletic Conference (WAC).
The team was led by head coach Al Luginbill, in his third year.
They played home games at Jack Murphy Stadium[note 1] in San Diego, California.
They completed the season with a record of eight wins, four losses and one tie (8–4–1, 6–1–1 WAC).
The year finished with an appearance in the Freedom Bowl in Anaheim, California vs. the Tulsa Golden Hurricane.