Mercer County, Ohio

Mercer County
Mercer County courthouse
Location within the U.S. state of Ohio
Ohio's location within the U.S.
Coordinates: 40°32′N 84°38′W / 40.54°N 84.63°W / 40.54; -84.63
Country United States
State Ohio
FoundedJanuary 2, 1824
Named afterHugh Mercer
SeatCelina
Largest cityCelina
Area
  Total
473 sq mi (1,230 km2)
  Land462 sq mi (1,200 km2)
  Water11 sq mi (30 km2)  2.3%
Population
 (2020)
  Total
42,528
  Density90/sq mi (30/km2)
Time zoneUTC−5 (Eastern)
  Summer (DST)UTC−4 (EDT)
Congressional district5th
Websitewww.mercercountyohio.org

Mercer County is located in the U.S. state of Ohio. As of the 2020 census, the population was 42,528. Its county seat is Celina. The county was created in 1820 and later organized in 1824. It is named for Hugh Mercer, an officer in the American Revolutionary War.

Mercer County comprises the Celina, Ohio Micropolitan Statistical Area