Stephenson County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 33rd-largest in Illinois
The population of Stephenson County, Illinois is 44,042 as of the 2023 American Community Survey, making it the 33rd-largest county in Illinois. The median household income is $61,943, the median home value is $127,500, and the median age is 45.2.
The population of Stephenson County has declined 9.5% since 2010 (47,606 → 43,088), a -0.71% annualized rate.
44,042
Population
-0.71%
Annual growth
78
People / sq mi
$61,943
Median Income
$127,500
Median Home Value
Stephenson County covers 564 sq mi of land at 78.1 people per square mile.
About Stephenson County, IL
Stephenson County is a county in Illinois with a population of 44,042. It ranks #33 among counties in Illinois by population. The median age is 45.2, older than the national median. The population is 48.8% male and 51.2% female.
The median household income in Stephenson County is $61,943, below the US median of $74,580. 8.9% of residents live below the federal poverty level. Home values sit at a median of $127,500, with monthly rent averaging $764. The homeownership rate of 71.0% is higher than the national rate of 64.8%.
Educational attainment in Stephenson County reflects 21.7% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 10.2% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 20.9 minutes each way.
Stephenson County Population History (2010-2024)
The county of Stephenson County had a population of 47,606 in 2010 and 43,088 in 2024, a -9.5% growth over 14 years. The peak was 47,606 in 2010. Average annual growth rate: -0.71%.
43,088
Population (2024)
47,606
Population (2010)
47,606
Peak (2010)
-0.71%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 47,606 |
| 2011 | 47,328 |
| 2012 | 46,895 |
| 2013 | 46,683 |
| 2014 | 46,280 |
| 2015 | 45,680 |
| 2016 | 45,512 |
| 2017 | 44,998 |
| 2018 | 44,702 |
| 2019 | 44,371 |
| 2020 | 44,573 |
| 2021 | 44,130 |
| 2022 | 43,702 |
| 2023 | 43,347 |
| 2024 | 43,088 |
Race & Ethnicity
| White | 82.1% |
| Black or African American | 8.4% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 0.7% |
| Two or More Races | 0.0% |
Age & Sex
45.2
Median Age
51.2%
Female
48.8%
Male
23.9%
Age 65+
Age Distribution
Children (under 15): 17.3% · Seniors (65+): 23.9%
Income & Poverty
| Median household income | $61,943$-19,759 vs state |
| Mean household income | $78,072 |
| Per-capita income | $34,672 |
| Poverty rate | 8.9%+0.7% vs state |
| Unemployment rate | 2.8% |
| Employment-to-population | 56.7% |
Top Industries by Employment
The largest employment sector in Stephenson County is professional & business services, accounting for 26.7% of workers.
How residents commute
0.7%
Drive alone
2.6%
Carpool
77.2%
Public transit
10.2%
Work from home
20.9 min
Avg commute
Housing
$127,500$-123,000 vs state
Median home value
$764
Median rent
71.0%
Homeownership rate
21,375
Total housing units
91.1%
Occupied
8.9%
Vacant
29.0%
Renter-occupied
Social & access
94.8%
With health insurance
90.6%
With broadband internet
27.0%
Foreign-born
7.0%
Veterans (18+)
15.5%
With a disability
95.9%
Speak language other than English at home
Education
91.5%
High School+
21.7%
Bachelor's+
Largest cities in Illinois
Other counties in Illinois
Part of Illinois
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County rankings
Frequently Asked Questions
Stephenson County, Illinois has a population of 44,042 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 33rd-largest county in Illinois. Population density is 78 people per square mile.
The population of Stephenson County has declined 9.5% since 2010 (47,606 → 43,088), a -0.71% annualized rate.
The median household income in Stephenson County, Illinois is $61,943, with mean (average) household income of $78,072 and per-capita income of $34,672. 8.9% of residents live below the federal poverty level.
In Stephenson County, the largest racial and ethnic groups are White (82.1%), Black or African American (8.4%), Hispanic or Latino (0.7%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Stephenson County, Illinois is 45.2 years. Residents are 51.2% female and 48.8% male.
The median home value in Stephenson County is $127,500 and median monthly rent is $764. 71.0% of occupied housing units are owner-occupied. The county has 21,375 total housing units, 8.9% of which are vacant.
The largest employment sector in Stephenson County, Illinois is professional, scientific, and management services, employing 26.7% of workers. The unemployment rate is 2.8%.
Chicago is among the largest cities associated with Stephenson County, Illinois, with a population of 2,707,648.
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Statewide data for Illinois
Population, race, income, age, and trends across Illinois
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.