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. In 1838, Ohio's government announced a competition to select the design for a new Statehouse. From about fifty entries, three winners were selected: first prize was awarded to Henry Walter of Cincinnati, the second to Martin Thompson of New York, and the third to painter Thomas Cole, also of New York. However, the organizing commission responsible for choosing the winners was unable to agree on a final design for construction. 

When the cornerstone was laid on July 4, 1839, the commission was still without a final design. Consultation with New York architect Alexander Jackson Davis resulted in a composite design that merged some key features of the three winning entries, but it was rejected as being too expensive. Henry Walter, the first-place winner of the design contest, was chosen to supervise construction of the new capitol, and he began working on another composite design that was based largely on the design of third-place winner, Thomas Cole.

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 1848 when construction resumed.  Architects used during the final phases included:

• William Russell West and J.O. Sawyer of Cincinnati in 1848.
•  Nathan Kelley of Columbus was hired to supervise the design and construction of the building’s interiors in 1854.
• Isaiah Rogers, a well known architect based in Cincinnati, was recruited to supervise the final stages of the Statehouse's construction including the building's interior and distinctive rotunda and its enclosing cupola.

 Then buildings, grounds, and landscaping, were finally completed in 1861.  However, as the function of State government changed and expanded over the years, the fifty-four rooms the building originally held increased to 317 rooms by 1989.  In addition, the Supreme Court was moved to a separate building on the east side of Capitol Square in 1901 to alleviate crowding, and to give the court the prestige of its own building.