Fairfax County, officially the County of Fairfax, is a county in the Commonwealth of Virginia. With a population of 1,150,309 as of the 2020 census, it is the most populous county in Virginia, the most populous jurisdiction in the Washington metropolitan area, and the most populous location in the Washington–Baltimore combined statistical area. The county seat is Fairfax; however, because it is an independent city under Virginia law, the city of Fairfax is not part of the county.