The Washington Metropolitan Area, formally known as the Washington-Arlington-Alexandria, DC-VA-MD-WV MSA, is a U.S. Metropolitan Statistical Area (MSA) as defined by the United States Office of Management and Budget (OMB) as of November 2004. It is also part of the larger Baltimore-Washington Metropolitan Area. As of 2006, the population of the area was estimated to be 5,290,400.

Other federal agencies such as the Department of Homeland Security refer to part of the area as the National Capital Region.