Union County

Click here to view a map of Union County
Click here for the Union County Census Profile (2024)

Union County is located in central Ohio, bordered by Marion, Delaware, and Franklin Counties to the east, Madison County to the south, Logan and Champaign Counties to the west, and Hardin and Marion Counties to the north. As of the 2020 census, the population was 62,784. The county seat is Marysville. Union County is part of the Columbus, OH Metropolitan Statistical Area. The county was named for the union of several smaller counties that were merged to form Union County. It was originally settled by European Americans in the early 19th century, mostly by migrants from Virginia and Pennsylvania. The economy of Union County is diverse, with industries ranging from manufacturing to healthcare. The county is home to several large companies, including Honda of America Manufacturing and Scotts Miracle-Gro. Union County is home to several state parks, including Darby Bend Lakes Metro Park and Hoover Nature Preserve. The county is also home to the Union County Historical Society Museum.