Cap·i·tol / ˈkapitl/ (usu. the Capitol) 1. the seat of the U.S. Congress in Washington, DC. ∎  (cap·i·tol) a building housing a legislative assembly: 50,000 people marched on New Jersey's state capitol.2. the temple of Jupiter on the Capitoline Hill in ancient Rome.

Capitol Building in Washington, D.C., in which the US Congress convenes. The original architect was William Thornton, and the cornerstone was laid by George Washington in 1793. The British burned down the Capitol in 1814. Benjamin Latrobe and Charles Bulfinch worked on the restoration, which was completed in 1830. The dome reaches a height of 88m (288ft).

Capitol in ancient Rome, the temple of Jupiter Optimus Maximus on the Saturnian or Tarpeian (afterwards called Capitoline) Hill in ancient Rome; the name is sometimes applied to the whole hill, including the citadel. The Capitol in literary terms is often seen as a symbol of Rome.

In the US, Capitol (usually the Capitol) is the name of the seat of the US Congress in Washington DC. The term in an American context in fact goes back to the late 17th century, in Virginia. Capitol Hill is the region around the Capitol in Washington DC (often as an allusive reference to the US Congress itself).