| Year: | 2015 |
| Team: | Humboldt State Lumberjacks |
| Sport: | football |
| Conference: | Great Northwest Athletic Conference |
| Short Conf: | GNAC |
| Afcarank: | 16 |
| Record: | 10–2 |
| Conf Record: | 6–0 |
| Head Coach: | Rob Smith |
| Hc Year: | 8th |
| Off Coach: | Eric Tripp |
| Oc Year: | 8th |
| Stadium: | Redwood Bowl |
| Bowl: | NCAA Division II Second Round |
| Bowl Result: | L 7–54 at Northwest Missouri State |
The 2015 Humboldt State Lumberjacks football team represented Humboldt State University—now known as California State Polytechnic University, Humboldt—as a member of the Great Northwest Athletic Conference (GNAC) during the 2015 NCAA Division II football season. Led by eighth-year head coach Rob Smith, the Lumberjacks compiled an overall record of 10–2 with a mark of 6–0 in conference play, winning the GNAC title. Humboldt State was invited to play in the postseason for the first time since 1968. The Lumberjacks advanced to the NCAA Division II football championship playoffs, defeating of South Dakota in the first round before losing to the eventual national champion, Northwest Missouri State, in the second round. Humboldt State was ranked No. 16 in the final AFCA poll. The team outscored its opponents 468 to 238 for 2015 season, with an average score of 45–14 in the ten wins. Humboldt State played home games at the Redwood Bowl in Arcata, California.