Columbus is the capital and most populous city of the U.S. state of Ohio. With a population of 905,748 at the 2020 census, it is the 15th-most populous city in the U.S., second-most populous city in the Midwest, and third-most populous U.S. state capital. The Columbus metropolitan area, with an estimated 2.23 million residents, is the largest metropolitan area entirely in Ohio and 32nd-largest metropolitan area in the U.S. Columbus is the county seat of Franklin County; it also extends into Delaware and Fairfield counties.