| Year: | 2005 |
| Team: | Texas State Bobcats |
| Sport: | football |
| Conference: | Southland Conference |
| Short Conf: | SLC |
| Tsnrank: | 4 |
| Fcscoachrank: | 4 |
| Record: | 11–3 |
| Conf Record: | 5–1 |
| Head Coach: | David Bailiff |
| Hc Year: | 2nd |
| Cooff Coach1: | Blake Miller |
| Cooc1 Year: | 4th as OC, 5th overall |
| Cooff Coach2: | Frank Hernandez |
| Cooc2 Year: | 2nd as OC, 3rd overall |
| Def Coach: | Craig Naivar |
| Dc Year: | 2nd |
| Stadium: | Bobcat Stadium |
| Champion: | SLC co-champion |
| Bowl: | NCAA Division I-AA Semifinal |
| Bowl Result: | L 37–40 vs. Northern Iowa |
The 2005 Texas State Bobcats football team represented Texas State University–San Marcos as a member of the Southland Conference during the 2005 NCAA Division I-AA football season. The Bobcats were led by second-year head coach David Bailiff and played their home games at Bobcat Stadium in San Marcos, Texas. They finished the season with an overall record of 11–3 and a mark of 5–1 in conference play, sharing the SLC title with Nicholls State. Texas State qualified for the NCAA Division I-AA Football Championship defeating Georgia Southern in the first round and Cal Poly in the second round before falling to Northern Iowa in the semifinals.