San Antonio (/ˌsæn ænˈtoʊnioʊ/ SAN an-TOH-nee-oh; Spanish for "Saint Anthony") is a city in the U.S. state of Texas. It is the seventh-most populous city in the United States, second-most populous city in Texas and second-most populous city in the Southern U.S., with a population of 1.43 million at the 2020 census. The San Antonio metropolitan area, with an estimated 2.76 million residents, ranks as the third-largest metropolitan area in Texas and the 24th-largest in the nation. It is the county seat of Bexar County.
Founded in 1718 as a Spanish mission and colonial outpost, San Antonio became the first chartered civil settlement in present-day Texas in 1731. The city was named in 1691 by a Spanish expedition in honor of Saint Anthony of Padua. It was part of the Spanish Empire, then the Mexican Republic from 1821 to 1836, before joining the United States. Straddling the regional divide between South and Central Texas, San Antonio anchors the southwestern corner of an urban megaregion colloquially known as the Texas Triangle. It lies about 80 miles (130 km) from Austin along the I-35 corridor, and together the San Antonio–Austin metroplex is home to approximately 5 million people.