Columbus is the capital and most populous city of the U.S. state of Ohio. With a 2020 census population of 905,748, it is the 14th-most populous city in the U.S., the second-most populous city in the Midwest after Chicago, and the third-most populous U.S. state capital after Phoenix, Arizona and Austin, Texas. Columbus is the county seat of Franklin County; it also extends into Delaware and Fairfield counties.