Tulsa is the second-most-populous city in the U.S. state of Oklahoma and the 48th-most populous city in the United States. The population was 413,066 as of the 2020 census. It is the principal municipality of the Tulsa metropolitan area, a region with 1.06 million residents. The city serves as the county seat of Tulsa County, the most densely populated county in Oklahoma, with urban development extending into Osage, Rogers and Wagoner counties.