Oak Hill is a suburban unincorporated community located in Fairfax County, Virginia, United States. Located just east of Washington Dulles International Airport and south of the Dulles Toll and Access Roads. The town of Herndon lies immediately to the north, while the unincorporated community of Chantilly is adjacent to Oak Hill in the south. The United States Postal Service defines Oak Hill’s boundaries by way of its ZIP code, 20171. Franklin Farm, Floris and McNair are census-designated places located within the larger Oak Hill community.
As an unincorporated area, Oak Hill’s boundaries are not officially defined by either a municipal government, the government of Fairfax County, or the U.S. Census Bureau.