Clark County is a county in Ohio, United States, about 45 miles west of Columbus and 25 miles northeast of Dayton. It had a population of 136,001 at the 2020 census, an estimated 135,158 by 2024, and covers 403 square miles (1,040 km2) centred near 39°55′N 83°47′W.
Springfield is the county seat and its only city with the county’s own courthouse; its postal code is 45505. The county holds 2 cities, 8 incorporated villages and 19 unincorporated communities across 10 townships, and it runs on Eastern Time. Its FIPS code is 39023.
Towns & Villages in Clark County
Clark County has 29 named places on record: 2 cities and 8 incorporated villages with their own local government, plus 19 unincorporated communities with none. Unincorp. covers crossroads and rural hamlets with no formal boundary or elected officials.
| Place | Type | Township | Pop. | ZIP |
|---|---|---|---|---|
| Springfield | City · seat | — | 58,662 | 45505 |
| New Carlisle | City | Bethel | 5,559 | 45344 |
| Enon | Village | Mad River | 2,449 | 45323 |
| South Charleston | Village | Madison | 1,706 | 45368 |
| North Hampton | Village | Pike | 457 | 45349 |
| South Vienna | Village | Harmony | 402 | 45369 |
| Tremont City | Village | German | 352 | 45372 |
| Donnelsville | Village | Bethel | 255 | 45319 |
| Catawba | Village | Pleasant | 245 | — |
| Clifton | Village | Green | 131 | 45316 |
| Beatty | Unincorp. | — | — | — |
| Brighton | Unincorp. | — | — | — |
| Cortsville | Unincorp. | — | — | — |
| Dialton | Unincorp. | — | — | — |
| Dodo | Unincorp. | — | — | — |
| Dolly Varden | Unincorp. | — | — | — |
| Durbin | Unincorp. | — | — | — |
| Eagle City | Unincorp. | — | — | — |
| Harmony | Unincorp. | Harmony | — | — |
| Hustead | Unincorp. | — | — | — |
| Limestone City | Unincorp. | — | — | — |
| Lisbon | Unincorp. | — | — | — |
| Locustgrove | Unincorp. | — | — | — |
| New Moorefield | Unincorp. | Moorefield | — | — |
| Pitchin | Unincorp. | — | — | — |
| Plattsburgh | Unincorp. | — | — | — |
| Selma | Unincorp. | — | — | — |
| Sugar Grove | Unincorp. | — | — | — |
| Villa | Unincorp. | — | — | — |
Two names on this list are easy to confuse with something else. Green Township is one of the county’s ten townships; Greene County, spelled with an extra E, is the separate county directly to Clark’s south — they are not the same place. Clifton itself straddles that same line: most of the village sits in Green Township here, but its southern edge crosses into Greene County.
Townships
| Township | Pop. (2020) | Main settlements |
|---|---|---|
| Bethel | 18,050 | New Carlisle, Donnelsville |
| Moorefield | 12,622 | New Moorefield, eastern Springfield suburbs |
| Springfield | 12,334 | surrounds the city of Springfield |
| Mad River | 10,984 | Enon |
| German | 7,578 | Tremont City, Durbin, Pitchin |
| Pike | 3,733 | North Hampton |
| Harmony | 3,652 | South Vienna |
| Pleasant | 3,143 | Catawba |
| Green | 2,711 | Clifton (partly) |
| Madison | 2,532 | South Charleston |
ZIP Codes
- 45501–45506 — Springfield (45505 covers downtown and the courthouse)
- 45344 — New Carlisle
- 45323 — Enon
- 45368 — South Charleston
- 45319 — Donnelsville
- 45349 — North Hampton
- 45369 — South Vienna
- 45372 — Tremont City
- 45316 — Clifton (shared with Greene County)
Catawba and the county’s unincorporated crossroads communities — Beatty, Brighton, Cortsville, Dialton, Dodo, Dolly Varden, Durbin, Eagle City, Hustead, Limestone City, Lisbon, Locustgrove, New Moorefield, Pitchin, Plattsburgh, Selma, Sugar Grove and Villa — have no ZIP of their own; mail there is delivered under the nearest incorporated town’s code.
Geography
Clark County sits in west-central Ohio’s till plains, low and gently rolling farmland shaped by glaciers. Of its 403 square miles, 397 are land and 5.1 are water, about 1.3 percent. The Mad River runs southwest across the county toward Dayton, and Buck Creek, also called Lagonda Creek, crosses Springfield before it is impounded east of the city as the C.J. Brown Reservoir inside Buck Creek State Park, a 4,016-acre park with over 2,100 acres of water.
Champaign County lies to the north, Madison County to the east, Greene County to the south, Montgomery County to the southwest, and Miami County to the west. Champaign County, Madison County, Greene County, Montgomery County and Miami County all border Clark directly.
Demographics
Clark County had a population of 136,001 at the 2020 census, and the latest estimate puts the county near 135,158 residents, a slight decline. Springfield and New Carlisle are by far the two largest communities, with Springfield alone holding well over a third of the county’s population. Median household income runs about $63,132, below Ohio’s statewide figure of $67,769 (2023 ACS). Population density works out to roughly 343 people per square mile of land, concentrated heavily around Springfield and the Bethel and Moorefield townships that flank it.
Economy & Local Life
Manufacturing employs the most workers in the county, about 10,221 people, followed by health care and social assistance at 8,926 and retail trade at 6,378. Topre, Silfex and McGregor Metal are among the manufacturing employers named in Springfield’s own labor-market profile. Wittenberg University and Clark State College, both based in Springfield, are the county’s two higher-education institutions and significant local employers in their own right. Since roughly 2018, Springfield’s manufacturing sector has drawn a growing Haitian immigrant community, an estimated 15,000 to 20,000 residents by 2024, many working under temporary protected status.
History
James Demint founded Springfield in 1801, naming it after Springfield, Massachusetts. Ohio’s legislature organized Clark County on 1 March 1818, naming it for General George Rogers Clark, a Revolutionary War officer, and Springfield became the county seat by a two-vote margin over the rival town of New Boston.
The National Road reached Springfield in 1838 and briefly made it the road’s western terminus, earning the city the nickname “Town at the End of the Pike” before the route was extended on to Richmond, Indiana. Springfield’s 19th-century farm-equipment industry, led by the Champion line built by the Warder, Bushnell & Glessner Company, later folded into International Harvester in 1902 and gave the city its longest-running nickname, “The Champion City.” In September 2024, Springfield drew national and international attention after baseless claims about its Haitian residents, amplified during that year’s presidential campaign, prompted bomb threats and school evacuations in the city.
Getting There
Interstate 70 crosses the southern part of the county. US Route 40 and US Route 68 run through Springfield, along with Ohio Route 72.
- Columbus — about 45 miles east
- Dayton — about 25 miles southwest
Dayton International Airport, about 27 miles southwest of Springfield, is the nearest major commercial airport. Springfield-Beckley Municipal Airport, roughly 6 miles south-southwest of downtown, handles general aviation. Clark County has no Amtrak service; the last passenger train through Springfield left the station on 30 April 1971.
Frequently Asked Questions
Where is Clark County located?
It sits in west-central Ohio, about 45 miles west of Columbus and 25 miles northeast of Dayton, bordered by Champaign, Madison, Greene, Montgomery and Miami counties.
What is the population of Clark County?
136,001 at the 2020 census, with a 2024 estimate near 135,158.
How big is Clark County?
403 square miles (1,040 km2), of which 397 square miles are land.
What is the county seat of Clark County?
Springfield is the county seat, founded in 1801 and chosen as seat by a two-vote margin in 1818.
How many towns and villages are in Clark County?
Two cities, Springfield and New Carlisle, plus eight incorporated villages: Enon, South Charleston, North Hampton, South Vienna, Tremont City, Donnelsville, Catawba and Clifton. Nineteen unincorporated communities round out the county.
What ZIP codes does Clark County use?
45501 through 45506 for Springfield; 45344 for New Carlisle; 45323, 45368, 45319, 45349, 45369, 45372 and 45316 for the county’s villages.
What is Clark County known for?
Springfield’s 19th-century “Champion City” farm-machinery industry, Wittenberg University and Clark State College, and Buck Creek State Park on the C.J. Brown Reservoir.
More counties in this state: Towns and villages in Ohio.