Butler County, Ohio

Butler County, Ohio
Location within the U.S. state of Ohio
Coordinates: 39°26′N 84°35′W / 39.44°N 84.58°W / 39.44; -84.58
Country United States
State Ohio
FoundedMay 1, 1803
Named afterGeneral Richard Butler
SeatHamilton
Largest cityHamilton
Area
 • Total
470 sq mi (1,200 km2)
 • Land467 sq mi (1,210 km2)
 • Water3.1 sq mi (8.0 km2)  0.7%
Population
 (2020)
 • Total
390,357
 • Estimate 
(2024)
399,542
 • Density836/sq mi (323/km2)
Time zoneUTC−5 (Eastern)
 • Summer (DST)UTC−4 (EDT)
Congressional district8th
Websitebcohio.gov

Butler County is a county located in the southwestern part of the U.S. state of Ohio. As of the 2020 census, the population was 390,357, making it the seventh-most populous county in Ohio. Its county seat and most populous city is Hamilton. It is named for General Richard Butler, who died in 1791 during St. Clair's defeat. Located along the Great Miami River, it is also home to Miami University, a public university founded in 1809. Butler County is part of the Cincinnati, OH-KY-IN Metropolitan Statistical Area.