Stephenson County, Illinois
Located in Illinois, Stephenson County has a population of 43,768 residents and a median age of 45.3 years, making it the #1,127 most populous county out of 3,222 nationwide. In terms of economic indicators, the county has a poverty rate of 13.9%. The median home value is $134,900, and the median household income is $64,043, which is 15% below the national median.
Demographics
Stephenson County has a population of 43,768, making it the #1,127 most populous county in the US. The median age is 45.3 years, which is 16.5% 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 Stephenson County is $64,043, ranking #1,701 out of 3,222 counties — 14.8% below the national median. The poverty rate is 13.9% and unemployment stands at 4.3%.
Median Household Income Trend
Rankings →Income Distribution
Industry of Employment
Occupation
Housing
The median home value in Stephenson County is $134,900 (-52.1% vs national). Renters pay a median of $798/mo and the homeownership rate is 70.9%.
Median Home Value Trend
Rankings →Household Type
Education
In Stephenson County, 20.7% of adults age 25+ hold a bachelor's degree or higher, which is 38.6% below the national average, ranking #1,874 out of 3,222 counties.
Bachelor's Degree or Higher Trend
Rankings →Health & Wellbeing
Life expectancy in Stephenson County is 76.2 years. 18.6% of adults report poor or fair health and 5.5% lack health insurance. Data from County Health Rankings (2025).
Life Expectancy Trend
Substance Use
18.3% of adults in Stephenson County smoke , 42.1% are obese , and 20.3% report excessive drinking. The drug overdose death rate is 13.7 per 100,000.
Adult Smoking Trend
Safety
The homicide rate in Stephenson County is 5.8 per 100,000 and the suicide rate is 15.8 per 100,000. Motor vehicle deaths occur at a rate of 14.1 per 100,000.
Homicide Rate Trend
Families & Children
17.5% of children in Stephenson County live in poverty and the infant mortality rate is 7.0 per 1,000 live births. The teen birth rate is 27.0 per 1,000 females age 15–19.
Infant Mortality Trend
Civic & Transportation
Voter turnout in Stephenson County is 63.5%. The mean commute time is 22.9 min, which is 17.1% below the national average.
Voter Turnout Trend
Mean Commute Time Trend
Rankings →Elections
In the 2024 presidential election, Stephenson County voted Republican with a margin of 19.4%. The vote was 39.5% Dem / 58.9% Rep. Compared to 2020, the margin shifted 3.7 toward Republicans .
Vote Share Over Time
About Stephenson County, Illinois
Stephenson County, Illinois has a total population of 43,768, making it the 1,127th most populous county in the United States. The median age in Stephenson County is 45.3 years, which is 16.5% above the national median of 38.9 years.
The median household income in Stephenson County is $64,043, which ranks #1,701 of 3,222 counties nationwide. This is 14.8% below the national median of $75,149. The poverty rate is 13.9%, higher than the national rate of 12.6%. The unemployment rate stands at 4.3%.
The median home value in Stephenson County is $134,900, 52.1% below the national median. Renters in Stephenson County pay a median gross rent of $798 per month. The homeownership rate is 70.9%, compared to the national rate of 64.4%.
In Stephenson County, 20.7% of residents aged 25 and older hold a bachelor's degree or higher, 38.6% below the national average of 33.7%. Health insurance coverage stands at 94.8% of the population. The average commute time for workers is 22.9 min.
Stephenson County is a diverse community. The largest racial or ethnic group is White (non-Hispanic) at 78.9% of the population, followed by Black (non-Hispanic) (8.5%) and Two or More Races (5.6%).
All data for Stephenson County, Illinois 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.