The 1989 SMU Mustangs football team represented Southern Methodist University (SMU) as a member of the Southwest Conference (SWC) during the 1989 NCAA Division I-A football season. Led by first-year head coach Forrest Gregg, the Mustangs compiled an overall record of 2–9 with a mark of 0–8 in conference play, placing last out of nine teams in the SWC. It was the first season played by SMU since 1986, after being issued the "death penalty" by the NCAA. The Mustangs offense scored 187 points while the defense allowed 499 points. In a game against the Houston Cougars on October 21, the Mustangs allowed 95 points.