Marion County, Iowa
Located in Iowa, Marion County has a population of 33,642 residents and a median age of 39.9 years, making it the #1,378 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 8.2%. The median home value is $233,000, and the median household income is $78,680, which is 5% above the national median.
Demographics
Marion County has a population of 33,642, making it the #1,378 most populous county in the US. The median age is 39.9 years, which is 2.6% above the national median.
Population Trend
Rankings →Year-over-Year Population Growth
Age & Sex Distribution
Race & Ethnicity
Nativity
Geographic Mobility (Past Year)
Economy
The median household income in Marion County is $78,680, ranking #639 out of 3,222 counties — 4.7% above the national median. The poverty rate is 8.2% and unemployment stands at 2.2%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Marion County is $233,000 (-17.3% vs national). Renters pay a median of $884/mo and the homeownership rate is 77.7%.
Median Home Value Trend
Rankings →Household Type
Education
In Marion County, 32.1% of adults age 25+ hold a bachelor's degree or higher, which is 4.7% below the national average, ranking #623 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Marion County is 78.2 years. 12.2% of adults report poor or fair health and 4.1% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
13.1% of adults in Marion County smoke , 38.3% are obese , and 25.2% report excessive drinking. The drug overdose death rate is 11.0 per 100,000.
Adult Smoking Trend
Safety
The suicide rate is 20.3 per 100,000. Motor vehicle deaths occur at a rate of 14.6 per 100,000.
Suicide Rate Trend
Families & Children
8.2% of children in Marion County live in poverty . The teen birth rate is 9.6 per 1,000 females age 15–19.
Teen Birth Rate Trend
Civic & Transportation
Voter turnout in Marion County is 76.2%. The mean commute time is 23.0 min, which is 16.6% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Marion County voted Republican with a margin of 37.8%. The vote was 30.4% Dem / 68.2% Rep. Compared to 2020, the margin shifted 4.1 toward Republicans .
Vote Share Over Time
About Marion County, Iowa
Marion County, Iowa has a total population of 33,642, making it the 1,378th most populous county in the United States. The median age in Marion County is 39.9 years, which is 2.6% above the national median of 38.9 years.
The median household income in Marion County is $78,680, which ranks #639 of 3,222 counties nationwide. This is 4.7% above the national median of $75,149. The poverty rate is 8.2%, lower than the national rate of 12.6%. The unemployment rate stands at 2.2%.
The median home value in Marion County is $233,000, 17.3% below the national median. Renters in Marion County pay a median gross rent of $884 per month. The homeownership rate is 77.7%, compared to the national rate of 64.4%.
In Marion County, 32.1% of residents aged 25 and older hold a bachelor's degree or higher, 4.7% below the national average of 33.7%. Health insurance coverage stands at 97.5% of the population. The average commute time for workers is 23.0 min.
Marion County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 93.3% of the population, followed by Hispanic or Latino (2.3%) and Two or More Races (2.3%).
All data for Marion County, Iowa comes from the U.S. Census Bureau's American Community Survey (ACS) 5-Year Estimates. These figures are estimates based on survey sampling and are subject to margin of error. For the most detailed and up-to-date data, visit the Census Bureau's official data portal.