Westfield High School is a public high school in unincorporated Fairfax County, Virginia, United States, west of the Chantilly CDP.It is a part of Fairfax County Public Schools (FCPS), serving students from the communities including Chantilly and Centreville as well as areas with Herndon addresses in grades 9–12. Opened in 2000, it is the head of the Westfield High School Pyramid in Cluster VIII. Westfield's main building has the same layout as South County High School (Fairfax County, Virginia). At 3,260 students, it is one of the largest four-year high schools in the Commonwealth of Virginia.The school was listed as the 46th best high school in the United States by Newsweek magazine in 2002 and 27th in the Washington, D.C., metropolitan area by The Washington Post in 2006 due to a high percentage of students enrolled in Westfield's Advanced Placement (AP) classes. Westfield shares a business partnership with Northrop Grumman's business IT group that entails sharing of buildings, as well as financial donations and gifts of supplies. It also shares an education partnership with Centreville Presbyterian Church to improve student achievement.