The Old Capitol Prison served a jail in Washington, DC during the time of the Civil War.

The building was built around 1800 as a tavern and boarding house on 1st Street in Washington. After the British burned the United States Capitol during the War of 1812, Congress leased this building for use as a temporary capitol from December 8, 1815 until 1825. Until the time of the Civil War, the building was used as a boarding house, a school, and other things.

During the time of the Civil War, the Union used the building as a prison for captured Confederates. The adjoining row of houses, Duff Green's Row, was also used as part of the prison. Famous inmates of the prison included Rose Greenhow and John Mosby.

• Detailed article on the prison