Plymouth County, Iowa Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 24th-largest in Iowa
The population of Plymouth County, Iowa is 25,699 as of the 2023 American Community Survey, making it the 24th-largest county in Iowa. The median household income is $81,600, the median home value is $218,600, and the median age is 41.1.
The population of Plymouth County has grown 3.4% since 2010 (24,978 → 25,825), a +0.24% annualized rate.
25,699
Population
+0.24%
Annual growth
30
People / sq mi
$81,600
Median Income
$218,600
Median Home Value
Plymouth County covers 863 sq mi of land at 29.8 people per square mile.
About Plymouth County, IA
The poverty rate is what most separates Plymouth County from the typical county: 4.1% of residents live below the federal poverty line, against 12.4% nationally. With 25,699 residents, Plymouth County is a county in Iowa. It ranks #24 among counties in Iowa by population.
The typical household earns $81,600 a year, near the US median of $78,538. Poverty is among the lowest of comparable US counties, at 4.1% — below the national 12.4%. Median home value is $218,600, with typical rent around $865.
Degree attainment is mid-range for US counties: 23.9% of adults hold a four-year degree, below the national 35.0%. About 8.6% of the workforce is home-based, below the national 14.0%, and the average commute runs about 19 minutes each way.
Plymouth County Population History (2010-2024)
The county of Plymouth County had a population of 24,978 in 2010 and 25,825 in 2024, a 3.4% growth over 14 years. The peak was 25,825 in 2024. Average annual growth rate: 0.24%.
25,825
Population (2024)
24,978
Population (2010)
25,825
Peak (2024)
0.24%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 24,978 |
| 2011 | 24,824 |
| 2012 | 24,836 |
| 2013 | 24,937 |
| 2014 | 24,918 |
| 2015 | 24,912 |
| 2016 | 25,207 |
| 2017 | 25,053 |
| 2018 | 25,024 |
| 2019 | 25,200 |
| 2020 | 25,694 |
| 2021 | 25,738 |
| 2022 | 25,714 |
| 2023 | 25,765 |
| 2024 | 25,825 |
Race & Ethnicity
| White | 90.5% |
| Black or African American | 2.4% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.0% |
| Two or More Races | 0.0% |
Age & Sex
41.1
Median Age
49.1%
Female
50.9%
Male
19.3%
Age 65+
Age Distribution
Children (under 15): 20.1% · Seniors (65+): 19.3%
Income & Poverty
| Median household income | $81,600+$8,453 vs state |
| Mean household income | $103,320 |
| Per-capita income | $42,241 |
| Poverty rate | 4.1%-2.8% vs state |
| Unemployment rate | 1.3% |
| Employment-to-population | 67.2% |
Top Industries by Employment
The largest employment sector in Plymouth County is professional & business services, accounting for 22.3% of workers.
How residents commute
0.4%
Drive alone
2.2%
Carpool
79.3%
Public transit
8.6%
Work from home
18.8 min
Avg commute
Housing
$218,600+$22,700 vs state
Median home value
$865
Median rent
73.7%
Homeownership rate
10,863
Total housing units
94.8%
Occupied
5.2%
Vacant
26.3%
Renter-occupied
Social & access
94.4%
With health insurance
93.7%
With broadband internet
18.8%
Foreign-born
7.8%
Veterans (18+)
11.8%
With a disability
92.4%
Speak language other than English at home
Education
94.2%
High School+
23.9%
Bachelor's+
Largest cities in Iowa
Other counties in Iowa
Part of Iowa
Metro areas in Iowa
County rankings
Frequently Asked Questions
Plymouth County, Iowa has a population of 25,699 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 24th-largest county in Iowa. Population density is 30 people per square mile.
The population of Plymouth County has grown 3.4% since 2010 (24,978 → 25,825), a +0.24% annualized rate.
The median household income in Plymouth County, Iowa is $81,600, with mean (average) household income of $103,320 and per-capita income of $42,241. 4.1% of residents live below the federal poverty level.
In Plymouth County, the largest racial and ethnic groups are White (90.5%), Black or African American (2.4%), Hispanic or Latino (1.0%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Plymouth County, Iowa is 41.1 years. Residents are 49.1% female and 50.9% male.
The median home value in Plymouth County is $218,600 and median monthly rent is $865. 73.7% of occupied housing units are owner-occupied. The county has 10,863 total housing units, 5.2% of which are vacant.
The largest employment sector in Plymouth County, Iowa is professional, scientific, and management services, employing 22.3% of workers. The unemployment rate is 1.3%.
Des Moines is among the largest cities associated with Plymouth 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.