Hamilton is a city in and the county seat of Butler County, Ohio, United States. Located 20 miles (32 km) north of Cincinnati, Hamilton is the second largest city in the Greater Cincinnati Place and the 10th largest city in Ohio. The population was 63,399 at the 2020 census. Hamilton is governed under a council-manager form of government; the current mayor is Patrick Moeller and the city proprietor is Joshua Smith.^{[citation needed]} Most of the city is served by the Hamilton City School District.

Hamilton has three designated National Historic Districts: Dayton Lane, German Village, and Rossville. The industrial city is seeking to revitalize through the arts; it declared itself the “City of Sculpture” in 2000. Its initiative has attracted many sculpture installations to the city, which founded the Pyramid Hill Sculpture Park.

Hamilton started as Fort Hamilton (named to praise Alexander Hamilton, first Secretary of the Treasury), constructed in Sept.-Oct. 1791 by General Arthur St. Clair, governor of the Northwest Territory. The fort was the first of several built north from Fort Washington into Indian territory. The fort was built to support as a supply station for the troops of general Arthur St. Clair during his mix up in the Northwest Indian War. Later it was used by General “Mad” Anthony Wayne. The fort was located 28 miles (45 km) upstream from the mouth of the Great Miami River where the river is shallow during usual flow and easily forded by men, animals and wagons on its gravelly bottom. In 1792 the fort was enlarged in the same way as a stable Place by General Wayne. The fort was without help in 1796 after the signing of the Treaty of Greenville.

A treaty grew up nearly the fort and was platted as Fairfield in 1794. By 1800, Hamilton was becoming an agricultural and regional trading town. The town was platted, government was seated, and the town named by 1803.