he Statehouse features a central recessed porch with a colonnade of a forthright and primitive Greek Doric mode, built of Columbus limestone that was quarried on the west banks of the Scioto River. A broad and low central pediment supports the windowed astylar drum, referred to as a Cupola, which contains an occulus that lights the interior rotunda.

Unlike many U.S. state capitol buildings, the Ohio Statehouse owes little to the architecture of the United States Capitol.

The Ohio Statehouse has been termed a supreme example of Greek Revival style. It is not patterned on one single building, but is a combination of stylistic elements from Greek sources, melded with contemporary needs and functions. The cupola shows direct influence by the Tholos of Delphi, a circular temple built about 360 BC. The Parthenon of Athens is also an influence. No ancient Greek building would have contained windows, but they were a major part of Greek Revival for a more practical reason: before electric light, sunlight was the major source of illumination.

When the state government relocated to the new city of Columbus in 1816, it occupied a modest two-story building on the corner of High and State Streets. When the cornerstone was laid on July 4, 1839, the commission was still without a final design from the winners of the design contest announced in 1838. Work on the building's foundation and lower level had only just begun when the Statehouse project encountered the first of many difficulties. The legislation that made Columbus the official capital city of Ohio was set to expire. While various factions within the government engaged in debate over relocating the capitol to another city, construction of the Statehouse was stopped. Open excavations were refilled with earth, and Capitol Square became open pasture for livestock.

The Statehouse remained neglected until February 1848 when William Russell West and J.O. Sawyer of Cincinnati were appointed architects and general supervisors of the project. By May of that same year construction had resumed. Unfortunately, a cholera epidemic began in Columbus, prompting widespread flight to the countryside by residents. Once the epidemic subsided, work on the Statehouse continued, interrupted only by intermissions during the harsh Ohio winters.