What is the largest city in Warren County, OH?

Mason is the largest city or town in Warren County, with about 35,509 residents.

How many ZIP codes are in Warren County?

Warren County includes 13 ZIP Code Tabulation Areas, including 45005, 45032, 45034, 45036, 45039.

What is the population of Warren County, OH?

About 250,008 people live in Warren County, based on American Community Survey 5-year estimates.

What counties border Warren County?

Warren County borders Hamilton County, Montgomery County, Butler County, Clermont County, Greene County, Clinton County.

Warren County, OH: Cities, ZIP Codes & Local Data

Population

250,008

Land area

401sq mi

People per sq mi

623

ZIP codes

13

Warren County at a glance

Warren County is about 2.2 times as dense as Ohio as a whole.
By population, it ranks 10th among 88 counties in Ohio.
The median household income is $110,132, 54% above the Ohio median of $71,389.
A typical owner-occupied home is valued at $349,400 (63% above Ohio) and median rent is $1,361 a month.
Its largest cities are Mason (35,509), Lebanon (21,501) and Springboro (19,980).

Local data for Warren County, OH

Counts from official public data

Housing and community stats

Warren County, OH, American Community Survey 2020-2024

Full profile

Median household income

$110,132

Poverty rate

6.0%

Median home value

$349,400

Prices +4.0% in a year

Median rent

$1,361/mo

Homeownership

79.4%

Bachelor's or higher

45.6%

Median age

40.1

Average commute

25.3 min

Largest reported origins and ancestries: German Americans (55,821), Irish Americans (30,624), Indian Americans (10,449).

Home values and rents Income, education and commute

Economy and federal money

Jobs, income, federal spending and pandemic loans

Details

Unemployment rate

3.2%

Sep 2026, -0.5 pts in a year

Average annual pay

$69,686

102,347 jobs, 2025

Income per person

$81,022

BEA, 2024

Federal spending

$1.4B

FY 2026, $5,791 per person

PPP loans

$401M

4,889 loans, 49,462 jobs reported

Campaign donations

$1.2M

Itemized, 2026 cycle

Economy Federal spending PPP loans

How people get to work

Warren County, OH, workers 16 and older. American Community Survey 5-year estimates

Drove alone73.7%
Carpooled5.9%
Public transit0.1%
Walked0.6%
Bicycle0.1%
Taxi, ride-hailing, motorcycle or other1.0%
Worked from home18.6%

Average one-way commute: 25.3 minutes for people who do not work from home.

Environment and hazard risk

Warren County, OH, from FEMA, NOAA and EPA

Full report

Natural hazard risk

Relatively Low

Top: ice storm

Storm events since 1996

816

Most often thunderstorm wind

Flood insurance policies

434

0.5% of homes, county

July high / Jan low

86° / 20°F

42.3 inches of rain a year

Hazards, floods and storm history Check a flood zone 30 historic places

Health statistics

Share of adults in Warren County, OH, CDC PLACES estimates

All 40 measures

Obesity

32.6%

U.S. 33.3% -0.7 pts

Diabetes

11.0%

U.S. 12.1% -1.1 pts

Smoking

12.2%

U.S. 12.8% -0.6 pts

Uninsured (18-64)

6.0%

U.S. 11.1% -5.1 pts

Cities, towns and ZIP codes in Warren County

Population shown

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Frequently asked questions

What is the largest city in Warren County, OH?: Mason is the largest city or town in Warren County, with about 35,509 residents.
How many ZIP codes are in Warren County?: Warren County includes 13 ZIP Code Tabulation Areas, including 45005, 45032, 45034, 45036, 45039.
What is the population of Warren County, OH?: About 250,008 people live in Warren County, based on American Community Survey 5-year estimates.
What counties border Warren County?: Warren County borders Hamilton County, Montgomery County, Butler County, Clermont County, Greene County, Clinton County.