Harrisburg is the capital city of the U.S. commonwealth of Pennsylvania and the seat of Dauphin County. With a population of 50,099 as of 2020, Harrisburg is the ninth-most populous city in Pennsylvania. It is the larger principal city of the Harrisburg–Carlisle metropolitan statistical area, also known as the Susquehanna Valley, which had a population of 591,712 in 2020 and is the fourth-most populous metro area in Pennsylvania.