• county
  • FIPS 39101
  • Largest town: Marion

Marion County, Ohio

Marion County had 64,976 residents in the Census Vintage 2024 estimate, on 403.8 square miles of land. It ranks 37th of 88 in Ohio by population and 75th by land area.

Population
64,976
#37 of 88 in Ohio · #844 in US
Area
403.8 sq mi
#75 of 88 in Ohio · #2,506 in US
Density
161 / sq mi
#32 of 88 in Ohio · #661 in US
Median household income
$56,991
#71 of 88 in Ohio · #2,134 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Marion County within Ohio. Pin: Columbus.

Measure from here

Tools and pages that start from Marion County

Marion County population, land area and income

Marion County had 64,976 residents in the Census Vintage 2024 estimate, on 403.8 square miles of land. It ranks 37th of 88 in Ohio by population and 75th by land area. That works out to 160.9 people per square mile, 1.7 times the US average of 96.3, and in the top quarter nationally.

The median county-equivalent in Ohio has 58,250 residents; Marion County is somewhat larger.

Its SAIPE 2023 median household income of $56,991 is below the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

64,976

3144th1st

844th of 3,144 (US)

Land area

404 sq mi

3144th1st

2506th of 3,144 (US)

Density

160.9 / sq mi

3144th1st

661st of 3,144 (US)

Median household income

$56,991

3143rd1st

2134th of 3,143 (US)

Rank within Ohio (88)

Population

64,976

88th1st

37th of 88 (OH)

Land area

404 sq mi

88th1st

75th of 88 (OH)

Density

160.9 / sq mi

88th1st

32nd of 88 (OH)

Median household income

$56,991

88th1st

71st of 88 (OH)

How Marion County's population changed since 2020

Marion County lost 414 residents between the July 2020 and July 2024 estimates, a drop of 0.6%. That ranks 56th of 88 in Ohio for growth. The median Ohio county changed by -0.2%, and the state as a whole by +0.7%.

Since the April 2020 estimates base, Marion County recorded 3,030 births and 3,664 deaths, a natural change of -634. Net international migration added +52 and net domestic migration, people moving to or from other US counties, came to +124. The largest single component was natural change, which removed 634 people.

65.4k202065.3k202164.6k202264.8k202365.0k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
3,030
Deaths
3,664
Net international migration
+52
Net domestic migration
+124
Change, July 2023 to July 2024
+148

Where Marion County is

The Census internal point of Marion County is at 40.588000, -83.168800. It sits in UTM zone 17N. The map shades Ohio's 88 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Marion County outlined. Dots are towns of 1,000+ people with residents in it.

Shelby County: -0.4%Defiance County: +1.0%Darke County: -0.8%Seneca County: -0.6%Wood County: +0.6%Fayette County: -0.7%Clark County: -0.7%Hocking County: -2.2%Jackson County: +0.2%Miami County: +2.7%Richland County: -0.1%Union County: +13.7%Auglaize County: -1.2%Hancock County: +0.1%Morgan County: -1.6%Van Wert County: -0.1%Hardin County: -1.0%Paulding County: -0.3%Portage County: +1.2%Delaware County: +10.6%Harrison County: -3.1%Ross County: -1.3%Crawford County: -0.9%Clinton County: -0.0%Henry County: -0.5%Pike County: -0.0%Cuyahoga County: -1.7%Highland County: +1.0%Knox County: +1.7%Ottawa County: -1.5%Huron County: -0.6%Erie County: -2.2%Holmes County: +1.0%Lawrence County: -4.0%Marion County: -0.6%Fairfield County: +5.2%Putnam County: -0.6%Guernsey County: -0.5%Vinton County: -2.1%Gallia County: -1.2%Trumbull County: -0.7%Wayne County: -0.2%Perry County: +0.6%Ashland County: -0.1%Fulton County: -1.4%Brown County: +1.4%Lucas County: -1.1%Stark County: -0.1%Medina County: +1.1%Belmont County: -2.4%Williams County: -1.4%Mahoning County: -1.0%Noble County: +1.1%Greene County: +2.5%Preble County: -0.5%Allen County: -1.2%Athens County: +1.3%Jefferson County: -2.0%Adams County: +0.8%Monroe County: -2.3%Washington County: -2.2%Logan County: -0.1%Franklin County: +2.4%Warren County: +5.3%Wyandot County: -2.1%Licking County: +3.4%Hamilton County: +0.8%Clermont County: +2.6%Butler County: +2.2%Coshocton County: +1.1%Geauga County: -0.0%Sandusky County: -0.0%Ashtabula County: -0.6%Carroll County: -0.9%Tuscarawas County: -1.2%Morrow County: +2.7%Montgomery County: +0.1%Mercer County: +0.3%Lake County: -0.1%Pickaway County: +6.0%Madison County: +3.8%Muskingum County: +0.1%Meigs County: -3.0%Columbiana County: -1.8%Lorain County: +2.7%Scioto County: -2.8%Champaign County: +0.4%Summit County: -0.3%
Change 2020 to 2024
  1. < -1.4%
  2. < -0.6%
  3. < -0.0%
  4. < +1.1%
  5. ≥ +1.1%
no data

Orange pin: Marion County internal point. Dark pin: Columbus.

Internal point

Decimal
40.588000, -83.168800
DMS
40°35'16.80"N 83°10'7.68"W
UTM
17N 316462.7E 4495283.4N
Geohash
dphygky64
Plus code
86GRHRQJ+6F

Towns in Marion County

2 incorporated places of 1,000+ people have residents in Marion County, 36,633 people together, or 56% of the county. Each figure counts only the part of the town inside Marion County; towns marked "part" extend into another county. The largest is Marion with 35,576.

  1. 01Marion35,576
  2. 02Prospect1,057
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Marion County

The Census 2024 county adjacency file lists 6 neighbors for Marion County. The most populous is Delaware County, OH, with 237,966 residents. Distances run between Census internal points in a straight line.

Distance to Columbus and the nearest big city

Columbus is 44.1 miles SSE of Marion County's internal point in a straight line. The nearest place of 100,000 or more is Columbus, OH (population 933,263), 42.9 miles away. The nearest place of 10,000 or more is Marion, OH (population 35,576), 2.5 miles away.

Marion County FIPS code

The FIPS code of Marion County is 39101: state code 39 for Ohio plus county code 101. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $56,991.

Questions people ask

What is the population of Marion County, Ohio?

The Census Vintage 2024 estimate for July 1, 2024 is 64,976. That is down 414 people (0.6%) from the July 2020 estimate of 65,390.

What is the FIPS code of Marion County?

39101. The first two digits (39) are Ohio; the last three (101) identify the county.

What is the largest town in Marion County?

Marion, with 35,576 residents inside Marion County in 2024.

Which counties border Marion County?

6 county-equivalents border it in the Census 2024 adjacency file: Delaware County, OH; Union County, OH; Crawford County, OH; Morrow County, OH; Hardin County, OH; Wyandot County, OH.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.