Springfield is a census-designated place in Fairfax County, Virginia, United States and a suburb of Washington, D.C. The Springfield CDP is recognized by the U.S. Census Bureau with a population of 30,484 as of the 2010 census. 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 area of the Washington Metropolitan Area and the most affluent region in the nation.Cite error: There are <ref> tags on this page, but the references will not show without a {{reflist}} template (see the help page).