Sierra Blanca is an unincorporated area in Hudspeth County, Texas, United States. It is also the county seat of the county and the namesake of a census-designated place (CDP) in which it is located. The town is part of the Trans-Pecos region of far West Texas, is located northeast of the Mexican border and is within the Mountain Time Zone. As of the 2020 census, its population was 315.

Hudspeth County is a county located in the U.S. state of Texas. As of the 2020 census, the population was 3,202. Its county seat is Sierra Blanca, and the largest community is Fort Hancock. The county is named for Claude Benton Hudspeth, a state senator and United States Representative from El Paso. It is northeast of the Mexico–U.S. border.