McNair is a census-designated place located in the Oak Hill section of Fairfax County, Virginia, United States. It is directly to the east of Washington Dulles International Airport. The population as of the 2020 census was 21,598. Much of the population resides in the McNair Farms planned community. The community has a school called McNair Elementary. McNair is also home to the Dulles Corner Business Park, home to the headquarters of Airbus Group, Inc. and Northrop Grumman Technical Services.