What is the largest city in Franklin County, MO?

Washington is the largest city or town in Franklin County, with about 15,130 residents.

How many ZIP codes are in Franklin County?

Franklin County includes 18 ZIP Code Tabulation Areas, including 63013, 63014, 63015, 63037, 63039.

What is the population of Franklin County, MO?

About 105,950 people live in Franklin County, based on American Community Survey 5-year estimates.

What counties border Franklin County?

Franklin County borders St. Louis County, St. Charles County, Jefferson County, Warren County, Washington County, Crawford County, Gasconade County.

Franklin County, MO: Cities, ZIP Codes & Local Data

Population

105,950

Land area

923sq mi

People per sq mi

115

ZIP codes

18

Franklin County at a glance

Franklin County is 27% denser than Missouri as a whole.
It is the 12th most populous of 115 counties in Missouri.
Households here earn a median of $73,165 a year, 3% more than the Missouri figure of $70,702.
A typical owner-occupied home is valued at $227,600 and median rent is $893 a month.
The biggest population centers are Washington (15,130), Union (12,781) and Pacific (7,475).

Local data for Franklin County, MO

Counts from official public data

Housing and community stats

Franklin County, MO, American Community Survey 2020-2024

Full profile

Median household income

$73,165

Poverty rate

8.2%

Median home value

$227,600

Prices +6.3% in a year

Median rent

$893/mo

Homeownership

76.5%

Bachelor's or higher

23.7%

Median age

41.8

Average commute

28.3 min

Largest reported origins and ancestries: German Americans (36,660), Irish Americans (14,885), Italian Americans (3,397).

Home values and rents Income, education and commute

Economy and federal money

Jobs, income, federal spending and pandemic loans

Details

Unemployment rate

3.0%

Sep 2026, -0.2 pts in a year

Average annual pay

$53,591

39,757 jobs, 2025

Income per person

$59,071

BEA, 2024

Federal spending

$733M

FY 2026, $7,002 per person

PPP loans

$153M

2,671 loans, 18,762 jobs reported

Campaign donations

$328K

Itemized, 2026 cycle

Economy Federal spending PPP loans

How people get to work

Franklin County, MO, workers 16 and older. American Community Survey 5-year estimates

Drove alone78.0%
Carpooled9.6%
Public transit0.2%
Walked1.3%
Bicycle0.0%
Taxi, ride-hailing, motorcycle or other0.6%
Worked from home10.3%

Average one-way commute: 28.3 minutes for people who do not work from home.

Environment and hazard risk

Franklin County, MO, from FEMA, NOAA and EPA

Full report

Natural hazard risk

Relatively Moderate

Top: strong wind

Storm events since 1996

721

Most often hail

Flood insurance policies

156

0.3% of homes, county

July high / Jan low

91° / 23°F

45.0 inches of rain a year

Hazards, floods and storm history Check a flood zone 49 historic places

Health statistics

Share of adults in Franklin County, MO, CDC PLACES estimates

All 40 measures

Obesity

39.6%

U.S. 33.3% +6.3 pts

Diabetes

12.2%

U.S. 12.1% about the same

Smoking

16.4%

U.S. 12.8% +3.6 pts

Uninsured (18-64)

8.1%

U.S. 11.1% -3.0 pts

Cities, towns and ZIP codes in Franklin County

Population shown

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Frequently asked questions

What is the largest city in Franklin County, MO?: Washington is the largest city or town in Franklin County, with about 15,130 residents.
How many ZIP codes are in Franklin County?: Franklin County includes 18 ZIP Code Tabulation Areas, including 63013, 63014, 63015, 63037, 63039.
What is the population of Franklin County, MO?: About 105,950 people live in Franklin County, based on American Community Survey 5-year estimates.
What counties border Franklin County?: Franklin County borders St. Louis County, St. Charles County, Jefferson County, Warren County, Washington County, Crawford County, Gasconade County.