Rock Island County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 14th-largest in Illinois
The population of Rock Island County, Illinois is 142,995 as of the 2023 American Community Survey, making it the 14th-largest county in Illinois. The median household income is $66,768, the median home value is $144,700, and the median age is 40.3.
The population of Rock Island County has declined 3.3% since 2010 (147,613 → 142,731), a -0.24% annualized rate.
142,995
Population
-0.24%
Annual growth
334
People / sq mi
$66,768
Median Income
$144,700
Median Home Value
Rock Island County covers 427 sq mi of land at 334.5 people per square mile.
About Rock Island County, IL
Rock Island County is a county in Illinois with a population of 142,995. It ranks #14 among counties in Illinois by population. The median age is 40.3, older than the national median. The population is 49.5% male and 50.5% female.
The median household income in Rock Island County is $66,768, below the US median of $74,580. 11.1% of residents live below the federal poverty level. Home values sit at a median of $144,700, with monthly rent averaging $863. The homeownership rate of 68.6% is higher than the national rate of 64.8%.
Educational attainment in Rock Island County reflects 24.1% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 6.7% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 20.2 minutes each way.
Rock Island County Population History (2010-2024)
The county of Rock Island County had a population of 147,613 in 2010 and 142,731 in 2024, a -3.3% growth over 14 years. The peak was 147,699 in 2012. Average annual growth rate: -0.24%.
142,731
Population (2024)
147,613
Population (2010)
147,699
Peak (2012)
-0.24%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 147,613 |
| 2011 | 147,474 |
| 2012 | 147,699 |
| 2013 | 147,686 |
| 2014 | 147,090 |
| 2015 | 146,161 |
| 2016 | 144,977 |
| 2017 | 143,824 |
| 2018 | 142,522 |
| 2019 | 141,775 |
| 2020 | 144,360 |
| 2021 | 142,943 |
| 2022 | 141,812 |
| 2023 | 141,939 |
| 2024 | 142,731 |
Race & Ethnicity
| White | 73.0% |
| Black or African American | 11.0% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.4% |
| Two or More Races | 0.2% |
Age & Sex
40.3
Median Age
50.5%
Female
49.5%
Male
20.1%
Age 65+
Age Distribution
Children (under 15): 18.7% · Seniors (65+): 20.1%
Income & Poverty
| Median household income | $66,768$-14,934 vs state |
| Mean household income | $83,668 |
| Per-capita income | $35,753 |
| Poverty rate | 11.1%+2.9% vs state |
| Unemployment rate | 3.5% |
| Employment-to-population | 57.7% |
Top Industries by Employment
The largest employment sector in Rock Island County is professional & business services, accounting for 22.5% of workers.
How residents commute
1.5%
Drive alone
3.2%
Carpool
79.1%
Public transit
6.7%
Work from home
20.2 min
Avg commute
Housing
$144,700$-105,800 vs state
Median home value
$863
Median rent
68.6%
Homeownership rate
66,742
Total housing units
91.7%
Occupied
8.3%
Vacant
31.4%
Renter-occupied
Social & access
94.0%
With health insurance
93.7%
With broadband internet
26.4%
Foreign-born
7.2%
Veterans (18+)
15.1%
With a disability
86.5%
Speak language other than English at home
Education
90.2%
High School+
24.1%
Bachelor's+
Largest cities in Illinois
Other counties in Illinois
Part of Illinois
Metro areas in Illinois
County rankings
Frequently Asked Questions
Rock Island County, Illinois has a population of 142,995 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 14th-largest county in Illinois. Population density is 334 people per square mile.
The population of Rock Island County has declined 3.3% since 2010 (147,613 → 142,731), a -0.24% annualized rate.
The median household income in Rock Island County, Illinois is $66,768, with mean (average) household income of $83,668 and per-capita income of $35,753. 11.1% of residents live below the federal poverty level.
In Rock Island County, the largest racial and ethnic groups are White (73.0%), Black or African American (11.0%), Hispanic or Latino (1.4%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Rock Island County, Illinois is 40.3 years. Residents are 50.5% female and 49.5% male.
The median home value in Rock Island County is $144,700 and median monthly rent is $863. 68.6% of occupied housing units are owner-occupied. The county has 66,742 total housing units, 8.3% of which are vacant.
The largest employment sector in Rock Island County, Illinois is professional, scientific, and management services, employing 22.5% of workers. The unemployment rate is 3.5%.
Chicago is among the largest cities associated with Rock Island 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.