O'Brien County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 56th-largest in Iowa
The population of O'Brien County, Iowa is 14,103 as of the 2023 American Community Survey, making it the 56th-largest county in Iowa. The median household income is $68,216, the median home value is $158,900, and the median age is 39.8.
The population of O'Brien County has declined 1.0% since 2010 (14,405 → 14,260), a -0.07% annualized rate.
14,103
Population
-0.07%
Annual growth
25
People / sq mi
$68,216
Median Income
$158,900
Median Home Value
O'Brien County covers 573 sq mi of land at 24.6 people per square mile.
About O'Brien County, IA
O'Brien County is a county in Iowa with a population of 14,103. It ranks #56 among counties in Iowa by population. The median age is 39.8, in line with the national median. The population is 49.9% male and 50.1% female.
The median household income in O'Brien County is $68,216, below the US median of $74,580. 9.1% of residents live below the federal poverty level. Home values sit at a median of $158,900, with monthly rent averaging $770. The homeownership rate of 77.3% is higher than the national rate of 64.8%.
Educational attainment in O'Brien County reflects 22.5% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 6.2% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 18.4 minutes each way.
O'Brien County Population History (2010-2024)
The county of O'Brien County had a population of 14,405 in 2010 and 14,260 in 2024, a -1.0% growth over 14 years. The peak was 14,405 in 2010. Average annual growth rate: -0.07%.
14,260
Population (2024)
14,405
Population (2010)
14,405
Peak (2010)
-0.07%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 14,405 |
| 2011 | 14,217 |
| 2012 | 14,154 |
| 2013 | 14,046 |
| 2014 | 14,045 |
| 2015 | 13,927 |
| 2016 | 13,921 |
| 2017 | 13,777 |
| 2018 | 13,806 |
| 2019 | 13,796 |
| 2020 | 14,149 |
| 2021 | 14,048 |
| 2022 | 14,107 |
| 2023 | 14,067 |
| 2024 | 14,260 |
Race & Ethnicity
| White | 89.9% |
| Black or African American | 1.3% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 0.6% |
| Two or More Races | 0.0% |
Age & Sex
39.8
Median Age
50.1%
Female
49.9%
Male
21.1%
Age 65+
Age Distribution
Children (under 15): 20.7% · Seniors (65+): 21.1%
Income & Poverty
| Median household income | $68,216$-4,931 vs state |
| Mean household income | $81,625 |
| Per-capita income | $34,346 |
| Poverty rate | 9.1%+2.2% vs state |
| Unemployment rate | 0.8% |
| Employment-to-population | 63.6% |
Top Industries by Employment
The largest employment sector in O'Brien County is professional & business services, accounting for 26.9% of workers.
How residents commute
0.1%
Drive alone
2.0%
Carpool
82.3%
Public transit
6.2%
Work from home
18.4 min
Avg commute
Housing
$158,900$-37,000 vs state
Median home value
$770
Median rent
77.3%
Homeownership rate
6,544
Total housing units
88.5%
Occupied
11.5%
Vacant
22.7%
Renter-occupied
Social & access
96.4%
With health insurance
92.1%
With broadband internet
18.2%
Foreign-born
6.0%
Veterans (18+)
14.6%
With a disability
93.0%
Speak language other than English at home
Education
90.3%
High School+
22.5%
Bachelor's+
Largest cities in Iowa
Other counties in Iowa
Part of Iowa
Metro areas in Iowa
County rankings
Frequently Asked Questions
O'Brien County, Iowa has a population of 14,103 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 56th-largest county in Iowa. Population density is 25 people per square mile.
The population of O'Brien County has declined 1.0% since 2010 (14,405 → 14,260), a -0.07% annualized rate.
The median household income in O'Brien County, Iowa is $68,216, with mean (average) household income of $81,625 and per-capita income of $34,346. 9.1% of residents live below the federal poverty level.
In O'Brien County, the largest racial and ethnic groups are White (89.9%), Black or African American (1.3%), Hispanic or Latino (0.6%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in O'Brien County, Iowa is 39.8 years. Residents are 50.1% female and 49.9% male.
The median home value in O'Brien County is $158,900 and median monthly rent is $770. 77.3% of occupied housing units are owner-occupied. The county has 6,544 total housing units, 11.5% of which are vacant.
The largest employment sector in O'Brien County, Iowa is professional, scientific, and management services, employing 26.9% of workers. The unemployment rate is 0.8%.
Des Moines is among the largest cities associated with O'Brien County, Iowa, with a population of 212,464.
More from Iowa
Population 497,441
Population 229,463
Population 174,302
Population 154,881
Full rankings of Iowa counties
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.