Austin is the capital city of the U.S. state of Texas. With a population of 961,855 at the 2020 census, it is the 12th-most populous city in the U.S., fifth-most populous city in Texas, and second-most populous U.S. state capital, while the Austin metro area with an estimated 2.55 million residents is the 25th-largest metropolitan area in the nation. Austin is the county seat and most populous city of Travis County, with portions extending into Hays and Williamson counties. Incorporated on December 27, 1839, it has been one of the fastest-growing large cities in the United States since 2010.