San Angelo is a city in and the county seat of Tom Green County, Texas, United States. It is in the Concho Valley, a region of West Texas between the Permian Basin to the northwest, Chihuahuan Desert to the southwest, Osage Plains to the northeast, and Central Texas to the southeast. According to the 2020 United States Census, San Angelo had a population of 99,893. It is the principal city and center of the San Angelo metropolitan area, which had a population of 121,516.