Newington is a census-designated place (CDP) in Fairfax County, Virginia, United States. As of the 2020 census, the population was 13,223. The population was 12,943 at the 2010 census. The 2010 census showed a significant decrease after half the population was split off to the newly created Newington Forest CDP.

Springfield is a census-designated place (CDP) in Fairfax County, Virginia, United States. The Springfield CDP is recognized by the U.S. Census Bureau with a population of 31,339 as of the 2020 census. Previously, per the 2010 census, the population was 30,484. Homes and businesses in bordering CDPs including North Springfield, West Springfield, and Newington are usually given a Springfield mailing address. The population of the collective areas with Springfield addresses is estimated to exceed 100,000. The CDP is a part of Northern Virginia, the most populous region of the Washington Metropolitan Area.