The 2015 Lamar Cardinals football team represented Lamar University in the 2015 NCAA Division I FCS football season. The Cardinals were led by sixth-year head coach Ray Woodard and played their home games at Provost Umphrey Stadium. They are a member of the Southland Conference. The Cardinals finished the season with a 5–6 record overall. In Southland Conference play, the Cardinals finished in a three-way tie for fifth place with a 4–5 conference record.