Marion County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 21st-largest in Iowa
The population of Marion County, Iowa is 33,551 as of the 2023 American Community Survey, making it the 21st-largest county in Iowa. The median household income is $78,059, the median home value is $211,100, and the median age is 39.7.
The population of Marion County has grown 2.5% since 2010 (33,225 → 34,048), a +0.17% annualized rate.
33,551
Population
+0.17%
Annual growth
61
People / sq mi
$78,059
Median Income
$211,100
Median Home Value
Marion County covers 554 sq mi of land at 60.5 people per square mile.
About Marion County, IA
Marion County is a county in Iowa with a population of 33,551. It ranks #21 among counties in Iowa by population. The median age is 39.7, in line with the national median. The population is 50.2% male and 49.8% female.
The median household income in Marion County is $78,059, near the US median of $74,580. 4.4% of residents live below the federal poverty level. Home values sit at a median of $211,100, with monthly rent averaging $880. The homeownership rate of 77.7% is higher than the national rate of 64.8%.
Educational attainment in Marion County reflects 33.1% of adults 25 and older holding a bachelor's degree or higher, near the national average of 34.3%. Roughly 9.7% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 20.4 minutes each way.
Marion County Population History (2010-2024)
The county of Marion County had a population of 33,225 in 2010 and 34,048 in 2024, a 2.5% growth over 14 years. The peak was 34,048 in 2024. Average annual growth rate: 0.18%.
34,048
Population (2024)
33,225
Population (2010)
34,048
Peak (2024)
0.18%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 33,225 |
| 2011 | 33,274 |
| 2012 | 33,277 |
| 2013 | 33,019 |
| 2014 | 33,280 |
| 2015 | 33,123 |
| 2016 | 33,157 |
| 2017 | 33,107 |
| 2018 | 33,251 |
| 2019 | 33,280 |
| 2020 | 33,414 |
| 2021 | 33,450 |
| 2022 | 33,582 |
| 2023 | 33,718 |
| 2024 | 34,048 |
Race & Ethnicity
| White | 94.8% |
| Black or African American | 0.5% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 0.4% |
| Two or More Races | 0.0% |
Age & Sex
39.7
Median Age
49.8%
Female
50.2%
Male
18.9%
Age 65+
Age Distribution
Children (under 15): 18.8% · Seniors (65+): 18.9%
Income & Poverty
| Median household income | $78,059+$4,912 vs state |
| Mean household income | $100,349 |
| Per-capita income | $40,540 |
| Poverty rate | 4.4%-2.5% vs state |
| Unemployment rate | 1.2% |
| Employment-to-population | 63.6% |
Top Industries by Employment
The largest employment sector in Marion County is professional & business services, accounting for 25.7% of workers.
How residents commute
0.2%
Drive alone
3.7%
Carpool
79.1%
Public transit
9.7%
Work from home
20.4 min
Avg commute
Housing
$211,100+$15,200 vs state
Median home value
$880
Median rent
77.7%
Homeownership rate
14,268
Total housing units
94.0%
Occupied
6.0%
Vacant
22.3%
Renter-occupied
Social & access
97.5%
With health insurance
93.4%
With broadband internet
20.1%
Foreign-born
7.0%
Veterans (18+)
13.4%
With a disability
97.1%
Speak language other than English at home
Education
94.6%
High School+
33.1%
Bachelor's+
Largest cities in Iowa
Other counties in Iowa
Part of Iowa
Metro areas in Iowa
County rankings
Frequently Asked Questions
Marion County, Iowa has a population of 33,551 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 21st-largest county in Iowa. Population density is 61 people per square mile.
The population of Marion County has grown 2.5% since 2010 (33,225 → 34,048), a +0.17% annualized rate.
The median household income in Marion County, Iowa is $78,059, with mean (average) household income of $100,349 and per-capita income of $40,540. 4.4% of residents live below the federal poverty level.
In Marion County, the largest racial and ethnic groups are White (94.8%), Black or African American (0.5%), Hispanic or Latino (0.4%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Marion County, Iowa is 39.7 years. Residents are 49.8% female and 50.2% male.
The median home value in Marion County is $211,100 and median monthly rent is $880. 77.7% of occupied housing units are owner-occupied. The county has 14,268 total housing units, 6.0% of which are vacant.
The largest employment sector in Marion County, Iowa is professional, scientific, and management services, employing 25.7% of workers. The unemployment rate is 1.2%.
Des Moines is among the largest cities associated with Marion County, Iowa, with a population of 212,464.
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Statewide data for Iowa
Population, race, income, age, and trends across Iowa
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.