Ohio Building, High-rise office building in Downtown Toledo, United States.

The Ohio Building is a twelve-story office structure at the intersection of Madison Avenue and Superior Street in downtown Toledo. The building rises approximately 178 feet and forms part of the central business district's skyline.

The structure was built in 1906 by the Ohio Savings Bank and Trust Company during a period of financial growth in early twentieth-century Toledo. The project reflected the city's economic strength and expanding business sector at that time.

George S. Mills designed the Ohio Building and moved his architectural offices into it once it was finished in 1906. A 1910 description called it "one of the finest structures in the state", a phrase that shows how the building was regarded in Toledo at the time.

The Ohio Building stands at 420 Madison Avenue, at the corner of Madison Avenue and Superior Street in downtown Toledo. It is a working office building, so the exterior is what visitors can see; the address makes it easy to locate on foot within the business district.

George S. Mills designed the Ohio Building and moved his architectural offices into it once construction finished in 1906, so the architect worked in the building he had planned. The 1910 description called it "one of the finest structures in the state".