The 2008 Cal Poly Mustangs football team represented California Polytechnic State University, San Luis Obispo as member of the Great West Conference (GWC) during the 2008 NCAA Division I FCS football season.
Led by Rich Ellerson in his eighth and final season as head coach, Cal Poly compiled an overall record of 8–3 with a mark of 3–0 in conference play, winning GWC title.
The Mustangs advanced to the NCAA Division I Football Championship playoffs, where they lost to Weber State in the first round.
Cal Poly played home games at Alex G. Spanos Stadium in San Luis Obispo, California.
Ellerson finished his eight-year tenure as head coach with a record of 56–34, for a winning percentage of .622.