Johnson County, Iowa
Located in Iowa, Johnson County has a population of 156,639 residents and a median age of 31.0 years, making it the #443 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 17.1%. The median home value is $308,600, and the median household income is $74,935, which is 0% below the national median.
Demographics
Johnson County has a population of 156,639, making it the #443 most populous county in the US. The median age is 31.0 years, which is 20.3% below 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 Johnson County is $74,935, ranking #845 out of 3,222 counties — 0.3% below the national median. The poverty rate is 17.1% and unemployment stands at 3.8%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Johnson County is $308,600 (+9.5% vs national). Renters pay a median of $1,122/mo and the homeownership rate is 59.4%.
Median Home Value Trend
Rankings →Household Type
Education
In Johnson County, 55.2% of adults age 25+ hold a bachelor's degree or higher, which is 63.7% above the national average, ranking #53 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Johnson County is 82.0 years. 13.4% of adults report poor or fair health and 5.0% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
12.8% of adults in Johnson County smoke , 30.9% are obese , and 26.6% report excessive drinking. The drug overdose death rate is 10.1 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in Johnson County is 1.4 per 100,000 and the suicide rate is 11.1 per 100,000. Motor vehicle deaths occur at a rate of 6.2 per 100,000.
Homicide Rate Trend
Families & Children
10.5% of children in Johnson County live in poverty and the infant mortality rate is 5.1 per 1,000 live births. The teen birth rate is 4.6 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in Johnson County is 76.1%. The mean commute time is 21.3 min, which is 22.9% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Johnson County voted Democratic with a margin of 38.1%. The vote was 68.4% Dem / 30.3% Rep. Compared to 2020, the margin shifted 5.2 toward Republicans .
Vote Share Over Time
About Johnson County, Iowa
Johnson County, Iowa has a total population of 156,639, making it the 443rd most populous county in the United States. The median age in Johnson County is 31.0 years, which is 20.3% below the national median of 38.9 years.
The median household income in Johnson County is $74,935, which ranks #845 of 3,222 counties nationwide. This is 0.3% below the national median of $75,149. The poverty rate is 17.1%, higher than the national rate of 12.6%. The unemployment rate stands at 3.8%.
The median home value in Johnson County is $308,600, 9.5% above the national median. Renters in Johnson County pay a median gross rent of $1,122 per month. The homeownership rate is 59.4%, compared to the national rate of 64.4%.
In Johnson County, 55.2% of residents aged 25 and older hold a bachelor's degree or higher, 63.7% above the national average of 33.7%. Health insurance coverage stands at 95.3% of the population. The average commute time for workers is 21.3 min.
Johnson County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 74.8% of the population, followed by Black (non-Hispanic) (7.6%) and Hispanic or Latino (6.7%).
All data for Johnson 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.