The Ohio Statehouse is the state capitol building and seat of government for the U.S. state of Ohio. The Greek Revival building is located on Capitol Square in Downtown Columbus. The capitol houses the Ohio General Assembly, consisting of the House of Representatives and the Senate. It also contains the ceremonial offices of the governor, lieutenant governor, state treasurer, and state auditor. Built between 1839 and 1861, it is one of the oldest working statehouses in the United States. The statehouse grounds include two other buildings, the Judiciary Annex or Senate Building, and the Atrium; the three are collectively referred to as the Ohio Statehouse into the present day.
The statehouse's prominent architecture has earned it several landmark designations, including as a National Historic Landmark. The building sees about 500,000 visitors per year.