Williamson County, Tennessee

Williamson County is a county in Tennessee, United States, about 21 miles south of Nashville.
It had a population of 247,726 at the 2020 census, an estimated 272,061 by 2024, and covers 584
square miles (1,510 km2) centred near 35°53′N 86°54′W.

Franklin is the county seat and the county’s largest city; its postal code is 37064. The
county holds 4 cities, 2 incorporated towns and about 15 unincorporated communities, and it runs
on Central Time. Its FIPS code is 47187.

Towns & Villages in Williamson County

Williamson County has 21 named places on record: 6 incorporated cities and towns and roughly
15 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.
Tennessee counties have no active civil township system, so this list has no township column.

Spring Hill straddles a county line the opposite way from a typical border town: its city
limits sit mostly inside Williamson County, but a substantial share of the built-up area extends
south into Maury County around the General Motors plant, so its 50,005 citywide residents are
split between the two counties, not counted whole for either. Allisona sits on the Williamson
line but its historic center and post office lie just across the border in Marshall County, so
most sources treat it as a Marshall County community with only its northern edge in Williamson.

ZIP Codes

• 37064 — Franklin (also covers Leiper’s Fork, which has no ZIP of its own)
• 37067 — Franklin (Cool Springs business district)
• 37068, 37065, 37069 — Franklin (P.O. box and secondary ZIPs)
• 37174 — Spring Hill
• 37027 — Brentwood
• 37135 — Nolensville
• 37062 — Fairview
• 37179 — Thompson’s Station
• 37046 — College Grove

Arrington, Bethesda, Boston, Brush Creek, Burwood, Duplex, Fernvale, Kirkland, Liberty Hill,
Peytonsville, Rudderville, Triune and Allisona have no ZIP code of their own; mail there is
delivered under Franklin, Nolensville or a neighboring county’s code depending on location.

Geography

Williamson County lies in Tennessee’s Central Basin and the Western Highland Rim, where
the rolling farmland of Middle Tennessee rises toward hillier country in the county’s west.
Of its 584 square miles, 582.8 are land and about 1.2 are water, a small share reflecting the
absence of any large reservoir. The Harpeth River and its tributary, the Little Harpeth River,
drain most of the county, running roughly north through Franklin and Brentwood before joining the
Cumberland River system downstream.

Davidson County, home to Nashville, borders Williamson to the north. Rutherford County lies to
the east, Marshall County to the south, Maury County to the southwest, Hickman County to the
west, and Dickson and Cheatham counties to the northwest. Davidson County, Rutherford County, Marshall County, Maury County, Hickman County, Dickson County and Cheatham County all border Williamson
directly.

Demographics

Williamson County had a population of 247,726 at the 2020 census, and the latest estimate
puts the county near 272,061 residents by 2024. Franklin and Spring Hill are the two largest
communities, together holding well over a third of the county’s population. Median household
income runs among the highest of any county in the United States, well above Tennessee’s
statewide figure of $67,631 (2023 ACS). Population density works out to roughly 425 people per
square mile of land, high for Middle Tennessee outside Davidson County, reflecting the
county’s position inside the Nashville-Davidson-Murfreesboro-Franklin metropolitan area.

Economy & Local Life

Health care employs a large share of the county’s workforce, led by Community Health
Systems, headquartered in Franklin with 3,923 local employees, and Williamson Medical Center with
1,900. Nissan North America runs a major operations campus in Franklin employing 1,550 people,
and Lee Company, a mechanical and facility-services firm, employs 1,616. In Spring Hill, General
Motors’ assembly and powertrain plant is the county’s largest manufacturing employer,
now paired with an Ultium Cells battery plant that began operating in 2024. Franklin’s
Cool Springs corridor anchors much of the county’s retail and office employment. The
county’s biggest annual event is the Pilgrimage Music and Cultural Festival in Franklin each
late September, which draws tens of thousands of visitors over a single weekend.

History

The Tennessee General Assembly established Williamson County on October 26, 1799, carving it
out of Davidson County. It was named for Hugh Williamson, a North Carolina physician and
politician who served three terms in the Continental Congress and helped draft the U.S.
Constitution. Franklin was founded the same year by Abram Maury Jr. and named for Benjamin
Franklin.

The county saw three Civil War engagements, the largest being the Second Battle of Franklin on
November 30, 1864, which produced nearly 10,000 casualties in a single afternoon. McGavock
Confederate Cemetery, next to the Carnton plantation house near Franklin, holds 1,481 soldiers and
is the largest private Confederate cemetery in the country. A third engagement, the Battle of
Thompson’s Station, was fought on March 5, 1863, near the present-day town of the same
name.

Getting There

Interstate 65 runs north-south through Franklin, Brentwood and Thompson’s Station.
Interstate 840 crosses the county’s southern half, and U.S. 31, U.S. 431 and State Route 96
serve the rest of the county.

• Nashville — about 21 miles north
• Murfreesboro — about 25 miles east
• Columbia — about 20 miles southwest
• Lewisburg — about 25 miles south

Nashville International Airport, roughly 25 miles northeast of Franklin, is the nearest major
commercial airport. John C. Tune Airport, on Nashville’s west side, and Downtown Franklin
Municipal Airport handle general aviation. Amtrak does not serve Williamson County; the nearest
station is in Nashville.

Frequently Asked Questions

Where is Williamson County located?
It sits in Middle Tennessee’s Central Basin, about 21 miles south of Nashville, bordered by
Davidson, Rutherford, Marshall, Maury, Hickman, Dickson and Cheatham counties.

What is the population of Williamson County?
247,726 at the 2020 census, with a 2024 estimate near 272,061.

How big is Williamson County?
584 square miles (1,510 km2), of which 582.8 square miles are land.

What is the county seat of Williamson County?
Franklin, founded in 1799, is the county seat and largest city.

How many towns and cities are in Williamson County?
Six incorporated places — Franklin, Spring Hill (partly), Brentwood, Nolensville, Fairview
and Thompson’s Station — plus roughly 15 unincorporated communities including College
Grove, Leiper’s Fork, Arrington and Triune.

What ZIP codes does Williamson County use?
37064, 37065, 37067, 37068 and 37069 for Franklin; 37174 for Spring Hill; 37027 for Brentwood;
37135 for Nolensville; 37062 for Fairview; 37179 for Thompson’s Station; and 37046 for
College Grove.

What is Williamson County known for?
Ranking as Tennessee’s wealthiest county, the Second Battle of Franklin in 1864, and the
General Motors and Ultium Cells plants in Spring Hill.

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