The Washington metropolitan area is the metropolitan area centered on Washington, D.C., the capital of the United States. The area includes all of the federal district and parts of the U.S. states of Maryland and Virginia, along with a small portion of West Virginia. While not a part of the Washington metropolitan area, St. Mary's County is part of the Baltimore–Washington metropolitan area.
The Washington metropolitan area is one of the most educated and most affluent metropolitan areas in the US. The metro area anchors the southern end of the densely populated Northeast megalopolis with an estimated total population of 6,133,552 as of the 2016 U.S. Census Bureau estimate, making it the sixth-largest metropolitan area in the nation and the largest metropolitan area in the Census Bureau's South Atlantic division.