Madison County, Ohio

Madison County is a county in Ohio, United States, about 25 miles southwest of Columbus, in the
Columbus, OH Metropolitan Statistical Area. It had a population of 43,824 at the 2020 census, an
estimated 46,985 by 2024, and covers 467 square miles (1,210 km2), of which 466 square miles are
land, centred near 39°54′N 83°24′W.

London is the county seat and Madison County’s only city; its postal code is 43140. The
county holds 1 city, 5 incorporated villages and 12 smaller unincorporated communities and
census-designated places across 14 townships, and it runs on Eastern Time. Its FIPS code is
39097.

Towns & Villages in Madison County

Madison County has 18 named places on record: London plus five incorporated villages, three
census-designated places (CDPs), and nine unincorporated communities with no local government of
their own. CDP stands for census designated place; Unincorp. covers crossroads and rural
communities with no formal boundary.

Plain City straddles two counties. Its 4,065 residents live mostly across the Union County
line, with only the village’s northeastern edge, in Darby Township, reaching into Madison
County — the population figure above is citywide, not the Madison County share alone. A
small annexed piece of Dublin, a Franklin County city, also touches the northeastern corner of
Madison County, but it carries no year-round population there.

Townships

Madison County has 14 civil townships. Township populations below exclude London, which is
counted separately as an independent city rather than as part of Union or Deer Creek Township.

ZIP Codes

• 43140 — London (also covers Choctaw Lake and most of Deer Creek Township)
• 43162 — West Jefferson
• 43064 — Plain City (shared with the Union County side of the village)
• 43143 — Mount Sterling
• 43153 — South Solon
• 43151 — Midway

Plumwood and Lafayette have no ZIP of their own; both are served under the 43140 London code.
Resaca sits on the boundary of the 43064 and 43140 ZIP areas. Big Plain, Kileville, Kiousville,
Lilly Chapel, Rosedale, Gillivan, Summerford and Newport lost their own post offices decades ago
and now receive mail through London or Plain City.

Geography

Madison County lies in the till plains of west-central Ohio, a nearly flat farming landscape
shaped by glaciers. Of its 467 square miles, 466 are land and 0.8 are water, about 0.2 percent
— the county has no large natural lake, and its biggest bodies of water are man-made:
Choctaw Lake, an impoundment on Deer Creek, and the London Country Club’s pond system near
the county seat. Big Darby Creek, a state and federal scenic river, forms part of the county’s
northeastern boundary through Darby Township, and Deer Creek and Little Darby Creek drain most of
the rest of the county toward the Scioto River.

Union County lies to the north, Franklin County to the east, Pickaway County to the southeast,
Fayette County to the south, Greene County to the southwest, Clark County to the west, and
Champaign County to the northwest. Union
County, Franklin County, Pickaway County, Fayette County, Greene County, Clark County and Champaign County all border Madison
directly.

Demographics

Madison County had a population of 43,824 at the 2020 census, and the latest Census Bureau
estimate puts the county near 46,985 residents by 2024. London and West Jefferson are the two
largest communities, together holding roughly a third of the county’s population. Median
household income runs near $87,045, well above Ohio’s statewide figure of $67,769 (2023
ACS). Population density works out to roughly 94 people per square mile of land, low for a county
this close to Columbus, reflecting how much of Madison County stays in row-crop agriculture even
inside the metro area.

Economy & Local Life

Manufacturing employs the most workers in the county, about 3,014 people, followed by retail
trade at 2,444 and health care and social assistance at 2,336. The London Correctional
Institution, a state prison in Union Township staffed by several hundred corrections employees,
is one of the county’s largest single employers. West Jefferson hosts an Amazon distribution
warehouse along US 40, and the Molly Caren Agricultural Center, an Ohio State University research
and extension farm on State Route 38 in Deer Creek Township, anchors the county’s
agricultural-education economy. The county’s biggest annual event is Farm Science Review,
held each September at the Molly Caren Center — Ohio State University’s College of
Food, Agricultural, and Environmental Sciences runs the three-day farm show, which drew about
112,000 visitors and more than 600 exhibitors at its most recent staging.

History

Ohio’s legislature formed Madison County on March 1, 1810, naming it for James Madison,
who was serving as president of the United States at the time. Patrick McLene laid out London as
the county seat in 1811.

In November 1949, workers uncovered the remains of a mastodon at Orleton Farms, about 11.5
miles northwest of West Jefferson — one of several Ice Age fossil finds in the till-plains
region. London Correctional Institution opened in 1913 as a branch of the Ohio Penitentiary and
became an independent prison in 1925; inmate labor built its main cell block under civilian
supervision, and the facility expanded after a 1930 fire at the Columbus penitentiary pushed the
state to add capacity in London.

Getting There

Interstates 70 and 71 both cross Madison County. US Routes 40, 42 and 62 also run through the
county, along with several state routes.

• Columbus — about 25 miles northeast
• Springfield — about 20 miles west
• Xenia — about 25 miles southwest
• Washington Court House — about 20 miles south

Madison County Airport, three miles north of London, handles general aviation; John Glenn
Columbus International Airport, roughly 30 miles northeast, is the nearest commercial airport.
Amtrak does not serve Madison County — the closest station is Cincinnati Union Terminal,
about 100 miles southwest, served three times a week by the Cardinal.

Frequently Asked Questions

Where is Madison County located?
It sits in west-central Ohio’s till plains, about 25 miles southwest of Columbus, bordered
by Union, Franklin, Pickaway, Fayette, Greene, Clark and Champaign counties.

What is the population of Madison County?
43,824 at the 2020 census, with a 2024 estimate near 46,985.

How big is Madison County?
467 square miles (1,210 km2), of which 466 square miles are land.

What is the county seat of Madison County?
London, laid out in 1811, is the county seat and the county’s only incorporated city.

How many towns and villages are in Madison County?
Five incorporated villages — West Jefferson, Plain City (partly), Mount Sterling, South
Solon and Midway — plus three census-designated places and nine smaller unincorporated
communities, alongside the city of London.

What ZIP codes does Madison County use?
43140 for London and Choctaw Lake, 43162 for West Jefferson, 43064 for Plain City, 43143 for
Mount Sterling, 43153 for South Solon and 43151 for Midway.

What is Madison County known for?
Farm Science Review each September at the Molly Caren Agricultural Center, one of the country’s
largest farm shows, and the 1949 mastodon fossil find near Orleton Farms.

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