The United States Capitol, often called The Capitol or the Capitol Building, is the meeting place of the United States Congress and the seat of the legislative branch of the U.S. federal government. It is located on Capitol Hill at the eastern end of the National Mall in Washington, D.C. Though no longer at the geographic center of the federal district, the Capitol forms the origin point for the district's street-numbering system and the district's four quadrants.

Central sections of the present building were completed in 1800. These were partly destroyed in the 1814 burning of Washington, then were fully restored within five years. The building was later enlarged by extending the wings for the chambers for the bicameral legislature, the House of Representatives in the south wing and the Senate in the north wing. The massive dome was completed around 1866 just after the American Civil War. Like the principal buildings of the executive and judicial branches, the Capitol is built in a neoclassical style and has a white exterior. Both its east and west elevations are formally referred to as fronts, though only the east front was intended for the reception of visitors and dignitaries.