Huntsville is a city in and the county seat of Walker County, Texas, United States. The population was 45,941 as of the 2020 census. It is the center of the Huntsville micropolitan area. Huntsville is in the East Texas Piney Woods on Interstate 45 and home to Sam Houston State University, Texas State Prison, the Texas Department of Criminal Justice, Huntsville State Park, and HEARTS Veterans Museum of Texas.