Sanderson is a census-designated place in and the county seat of Terrell County, Texas. The population was 664 at the 2020 census. Sanderson was created in 1882 as a part of neighboring Pecos County. It became the seat of Terrell County in 1905.
Terrell County is a county in the U.S. state of Texas. As of the 2020 census, its population was 760. Its county seat is the census-designated place of Sanderson; no incorporated municipalities are in the county. Terrell County comprises 2,357 square miles of rocky terrain with elevations ranging from 1,300 to 4,000 feet above sea level.