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.

Capitol Square is a public square in Downtown Columbus, Ohio. The square includes the Ohio Statehouse, its 10-acre (4.0 ha) Capitol Grounds, as well as the buildings and features surrounding the square. The Capitol Grounds are surrounded to the north and west by Broad and High Streets. These are the main thoroughfares of the city since its founding. They form the city's 100 percent corner. The grounds are surrounded by 3rd Street to the east and State Street to the south. The oldest building on Capitol Square, the Ohio Statehouse, is the center of the state government and roughly in the geographic center of Capitol Square, Columbus and Ohio.