South Riding is a census-designated place and planned community in Loudoun County, Virginia, United States. The South Riding homeowner association was founded in January 1995 to provide services to the community. Neighboring U.S. Route 50 and State Route 28 provide access to the Dulles/Reston/Tysons Corner technology corridor and other major employment centers in Northern Virginia and Washington, D.C. In 2020, the population was 33,877.