Located in the Northern Virginia portion of the Washington metropolitan area, Chantilly sits approximately 25 miles (40 km) west of Washington, D.C., via Interstate 66 and U.S. Route 50. It is located between Centreville to the south, Herndon and Reston to the north and northeast, respectively, and Fairfax 7 miles (11 km) to the southeast. U.S. Route 50 and Virginia State Route 28 intersect in Chantilly, and these highways provide access to the Dulles/Reston/Tysons Corner technology corridor and other major employment centers in Northern Virginia and Washington, D.C.
Residents of the CDP go to Fairfax County Public Schools. Elementary schools within the CDP include Brookfield Elementary School, Greenbriar East Elementary School, Greenbriar West Elementary School, Lees Corner Elementary School, Navy Elementary School, and Poplar Tree Elementary School. Rocky Run Middle School, Franklin Middle School, and Chantilly High School are located within the CDP. Westfield High School is a large high school located outside of the CDP. St. Timothy School and St. Veronica School, private Catholic schools, are located in the CDP.