Oakton is a census-designated place in Fairfax County, Virginia, United States. The population was 34,166 at the 2010 census. Oakton is an affluent community in Northern Virginia. Its center is 16 miles west of Washington, D.C.
Oakton is located in central Fairfax County at 38°52′59″N 77°17′24″W (38.883050, -77.289900). The area is traversed by Interstate 66 and Virginia State Route 123.
The CDP is bordered to the south by the city of Fairfax, to the west by Fair Oaks, to the northwest by Difficult Run, to the north by the Wolf Trap CDP, to the east by the town of Vienna, and to the southeast by Merrifield.
According to the United States Census Bureau, the CDP has a total area of 9.8 square miles (25.4 km2), of which 9.8 square miles (25.3 km2) is land and 0.04 square miles (0.1 km2), or 0.38%, is water.