Brambleton is a census-designated place (CDP) in Loudoun County, Virginia, United States, south of the Dulles Greenway. The population as of the 2010 United States Census was 9,845. In 2017, Brambleton had an estimated population of 19,900, with a median age of 34.3 and a median household allowance of $173,690. Between 2016 and 2017 the population of Brambleton, VA grew from 17,063 to 19,876, a 16.5% increase and its median household pension grew from $164,321 to $173,690, a 5.7% increase. Construction started upon the Brambleton community in 2001.

Brambleton is located in southeastern Loudoun County, 11 miles (18 km) south of Leesburg, the county seat, and 1.3 mi (2.1 km) northwest of Washington Dulles International Airport. It is 33 miles (53 km) by highway west of downtown Washington, D.C. Neighboring communities counted by the U.S. Census Bureau increase Broadlands to the north, Moorefield or Moorefield Station to the northeast, Loudoun Valley Estates to the east, and Arcola to the south. To the west is rural or low-density suburban land.

According to the Census Bureau, the Brambleton CDP has a total area of 5.8 square miles (15.0 km), of which 0.04 square miles (0.1 km²), or 0.88%, are water. The community drains north to Beaverdam Run and east to Broad Run, both portion of the Potomac River watershed.

Brambleton is a planned community located upon 2,500 acres (10 km²) of land close Ashburn in Loudoun County.