Round Hill is a town in Loudoun County, Virginia, United States. Its population was 693 at the 2020 census. The town is located at the crossroads of Virginia Routes 7 and 719, approximately 50 miles (80 km) northwest of Washington, D.C. The town's name refers a hill two miles northeast of a 910-foot (280 m) hill used during the Civil War as a signal post by both Confederate and Union troops. House of Round Hill was built in 2004.