Knox County, Ohio

Knox County is a county in Ohio, United States, in the east-central part of the state, about 40 miles northeast of Columbus. It had a population of 62,721 at the 2020 census, an estimated 64,002 by 2025, and covers 530 square miles (1,400 km2) centred near 40°23′N 82°28′W.

Mount Vernon is the county seat and the county’s only city; its postal code is 43050. The county holds 1 city, 6 incorporated villages and 4 census-designated places across 22 townships, and it runs on Eastern Time. Its FIPS code is 39083.

Towns & Villages in Knox County

Knox County has 11 named places on record: one city, six incorporated villages and four census-designated places (CDPs) with no local government of their own. Type column: “Town” covers the county’s incorporated villages, matching the label this site uses for small incorporated places across every state; CDP marks a community the Census Bureau tracks even though it has never incorporated.

Apple Valley, the county’s largest unincorporated place, is a planned community built around the 511-acre Apple Valley Lake and straddles Howard and Brown townships — the population above covers the whole CDP, not just its Howard Township portion. Bladensburg sits directly on the Clay–Jackson township line. One nearby village is deliberately left off this table: Utica, home to roughly 2,064 people, is mostly a Licking County place, with only a small edge of its platted area reaching into Knox County, so its population is not counted as part of this county.

Townships

Knox County’s 22 civil townships are listed below by population. Where a township hosts one of the incorporated places above, that population is already folded into the township total, except for Mount Vernon (excluded from Clinton Township’s count, since it is separately incorporated) and Fredericktown (excluded from Wayne Township’s count for the same reason).

ZIP Codes

• 43050 — Mount Vernon (also serves South Mount Vernon)
• 43019 — Fredericktown
• 43022 — Gambier
• 43011 — Centerburg
• 43014 — Danville
• 43037 — Martinsburg
• 43006 — Brinkhaven
• 43028 — Apple Valley (also serves Howard)
• 43005 — Bladensburg

Every incorporated place and CDP in Knox County carries its own ZIP or shares its nearest post office town’s code; none of the 11 places on the table above go without one.

Geography

Knox County sits on the Glaciated Allegheny Plateau, a belt of rolling hills shaped by the last ice age. About 58 percent of the county is farmland and 28 percent is forested. Of its 530 square miles, 525 are land and 4.1 are water, roughly 0.8 percent. The Kokosing River, a state-designated scenic river, runs through Mount Vernon and Gambier on its way toward the Walhonding and Muskingum river systems; the Mohican River crosses the county’s northeastern corner past Brinkhaven. Apple Valley Lake, a 511-acre reservoir built for the Apple Valley resort community, is the county’s largest lake.

Richland County borders Knox to the north, Ashland and Holmes counties to the northeast, Coshocton County to the east, Licking County to the south, Delaware County to the southwest, and Morrow County to the northwest. Richland County, Ashland County, Holmes County, Coshocton County, Licking County, Delaware County and Morrow County all border Knox County directly.

Demographics

Knox County had a population of 62,721 at the 2020 census, and the latest estimate puts the county near 64,002 residents by 2025. Mount Vernon and Apple Valley are the two largest named communities, together holding well over a third of the county’s population. Median household income runs $73,878, higher than Ohio’s statewide 2023 ACS figure of $67,769. Population density works out to about 122 people per square mile of land, low for central Ohio and typical of a county with no city larger than 17,000 residents.

Economy & Local Life

Health care and social assistance is the county’s largest employment sector, with about 4,461 workers, followed by manufacturing at 4,217 and educational services at 3,238. Siemens Energy and Ariel Corporation, a maker of natural gas compressor equipment, are among the county’s largest manufacturers, both based in Mount Vernon. Kokosing Construction Company, a major regional heavy-construction contractor, is headquartered in the county. Kenyon College in Gambier and Mount Vernon Nazarene University are the county’s two four-year colleges and significant local employers in their own right. Agriculture remains part of the county’s base, generating roughly $110 million a year from corn, soybeans and livestock. The Knox County Fair draws exhibitors and visitors from across the region each summer at the fairgrounds in Mount Vernon.

History

Ohio’s legislature organized Knox County on 1 March 1808, carving it out of Fairfield County, and named it for Henry Knox, a Revolutionary War general who became the first U.S. Secretary of War. Mount Vernon was founded in 1805, three years earlier, and named after George Washington’s Virginia estate; it became the county seat once the county organized.

Kenyon College opened in Gambier in 1824, founded by Episcopal bishop Philander Chase and named for one of the college’s early benefactors, Lord Gambier; it remains the defining institution of College Township two centuries later. On 4 May 2020, Gambier became the first municipality in Knox County to pass a law explicitly protecting LGBTQ+ people from discrimination. Mount Vernon’s Woodward Opera House, built in 1851 and later remodeled, is recognized as the oldest surviving theater of its kind in the United States.

Getting There

No interstate highway crosses Knox County. Ohio State Route 13 runs north–south through Fredericktown and Mount Vernon; US 36 crosses the county through Centerburg and Mount Vernon, meeting State Route 3 and State Route 229 there; State Route 95 meets SR 13 at Fredericktown.

• Columbus — about 40 miles southwest
• Newark — about 25 miles south
• Mansfield — about 25 miles north
• Coshocton — about 25 miles east

John Glenn Columbus International Airport, roughly 45 miles southwest of Mount Vernon, is the nearest major commercial airport. Knox County Airport, a general-aviation field about 4.6 miles southwest of downtown Mount Vernon, handles charter and private flights. Knox County has no Amtrak route; the closest station is in Cleveland, a considerable distance to the north.

Frequently Asked Questions

Where is Knox County located?
It sits in east-central Ohio, about 40 miles northeast of Columbus, bordered by Richland, Ashland, Holmes, Coshocton, Licking, Delaware and Morrow counties.

What is the population of Knox County?
62,721 at the 2020 census, with a 2025 estimate near 64,002.

How big is Knox County?
530 square miles (1,400 km2), of which 525 square miles are land.

Which city is the county seat of Knox County?
Mount Vernon, founded in 1805, is the county seat and the county’s only city.

How many towns and villages are in Knox County?
Six incorporated villages — Fredericktown, Gambier, Centerburg, Danville, Martinsburg and Brinkhaven — plus four census-designated places: Apple Valley, South Mount Vernon, Howard and Bladensburg.

What ZIP codes does Knox County use?
43050 for Mount Vernon and South Mount Vernon, 43019 for Fredericktown, 43022 for Gambier, 43011 for Centerburg, 43014 for Danville, 43037 for Martinsburg, 43006 for Brinkhaven, 43028 for Apple Valley and Howard, and 43005 for Bladensburg.

What is Knox County known for?
Kenyon College in Gambier, one of Ohio’s oldest liberal arts colleges, and the Mount Vernon-based Ariel Corporation, a major manufacturer of natural gas compressor equipment.

More counties in this state: Towns and villages in Ohio.