Union County is a county located in the U.S. state of Ohio. As of the 2020 census, the population was 62,784. Its county seat is Marysville. Its name is reflective of its origins, it being the union of portions of Franklin, Delaware, Madison, and... Wikipedia
Cities: Marysville, Richwood, Milford Center, and more
County seat: Marysville
Congressional district: 4th
Founded: April 1, 1820
Named for: formed from the union of parts of surrounding counties