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
The poverty rate is what most separates Marion County from the typical county: 4.4% of residents live below the federal poverty line, against 12.4% nationally. With 33,551 residents, Marion County is a county in Iowa. It ranks #21 among counties in Iowa by population.
The typical household earns $78,059 a year, near the US median of $78,538. Very few residents live in poverty — 4.4%, below the national 12.4%. The typical home is valued at $211,100, with typical rent around $880.
College attainment is above the local norm at 33.1%, below the national 35.0%. Remote work is below the national 14.0% at 9.7%, and the average commute runs about 20 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.