The following counties in Ohio have historic locations on the National Register of Historic places. Please select a county in Ohio to see the different historic places in the county.

Adams County Historic Locations	Allen County Historic Locations
Ashland County Historic Locations	Ashtabula County Historic Locations
Athens County Historic Locations	Auglaize County Historic Locations
Belmont County Historic Locations	Brown County Historic Locations
Butler County Historic Locations	Carroll County Historic Locations
Champaign County Historic Locations	Clark County Historic Locations
Clermont County Historic Locations	Clinton County Historic Locations
Columbiana County Historic Locations	Coshocton County Historic Locations
Crawford County Historic Locations	Cuyahoga County Historic Locations
Darke County Historic Locations	Defiance County Historic Locations
Delaware County Historic Locations	Erie County Historic Locations
Fairfield County Historic Locations	Fayette County Historic Locations
Franklin County Historic Locations	Fulton County Historic Locations
Gallia County Historic Locations	Geauga County Historic Locations
Greene County Historic Locations	Guernsey County Historic Locations
Hamilton County Historic Locations	Hancock County Historic Locations
Hardin County Historic Locations	Harrison County Historic Locations
Henry County Historic Locations	Highland County Historic Locations
Hocking County Historic Locations	Holmes County Historic Locations
Huron County Historic Locations	Jackson County Historic Locations
Jefferson County Historic Locations	Kenton County Historic Locations
Knox County Historic Locations	Lake County Historic Locations
Lawrence County Historic Locations	Licking County Historic Locations
Logan County Historic Locations	Lorain County Historic Locations
Lucas County Historic Locations	Madison County Historic Locations
Mahoning County Historic Locations	Marion County Historic Locations
Medina County Historic Locations	Meigs County Historic Locations
Mercer County Historic Locations	Miami County Historic Locations
Monroe County Historic Locations	Montgomery County Historic Locations
Morgan County Historic Locations	Morrow County Historic Locations
Muskingum County Historic Locations	Noble County Historic Locations
Ottawa County Historic Locations	Paulding County Historic Locations
Perry County Historic Locations	Pickaway County Historic Locations
Pike County Historic Locations	Portage County Historic Locations
Preble County Historic Locations	Putnam County Historic Locations
Richland County Historic Locations	Ross County Historic Locations
Sandusky County Historic Locations	Scioto County Historic Locations
Seneca County Historic Locations	Shelby County Historic Locations
Stark County Historic Locations	Summit County Historic Locations
Trumbull County Historic Locations	Tuscarawas County Historic Locations
Union County Historic Locations	Van Wert County Historic Locations
Vinton County Historic Locations	Warren County Historic Locations
Washington County Historic Locations	Wayne County Historic Locations
Williams County Historic Locations	Wood County Historic Locations
Wyandot County Historic Locations