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Demographics of Rock Island County, Illinois

Rock Island County, Illinois had 141,869 people on July 1, 2025, by the Census Bureau’s estimate: −2,488 since July 2020. Age, income, poverty, housing and origin below come from the American Community Survey, averaged over 2020–2024, each with its margin of error.

Rock Island County, in four figures

141,869
Population
July 1, 2025, Vintage 2025 estimate.
−1.7%
Change since July 2020
−2,488 people.
40.3 ±0.3
Median age
ACS 2020–⁠2024.
$67,159 ±$1,869
Median household income
ACS 2020–⁠2024, in 2024 dollars.

Population, year by year

July 1 estimates from the Census Bureau’s Vintage 2025. Each year's change is births less deaths, net moves from abroad and net moves from elsewhere in the country, with the Bureau's small residual. The 2020 row's components run 3 months, from the April census to July 1.

Rock Island County, Illinois's population shrank 1.7% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Rock Island County, Illinois's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).

Source: The Census Bureau

About this chart

The figures

Rock Island County, Illinois's population shrank 1.7% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Rock Island County, Illinois's resident population and the nation's, each year of the Census Bureau's Vintage 2025, as a share of its July 2020 level (= 100).
July 1PopulationIndexUnited States
2020144,357100.0100.0
2021142,48598.7100.2
2022140,97297.7100.7
2023140,90597.6101.6
2024141,59198.1102.5
2025141,86998.3103.1

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Population of Rock Island County, Illinois on July 1 of each year, Vintage 2025
July 1PopulationChange
2020144,357−312
2021142,485−1,872
2022140,972−1,513
2023140,905−67
2024141,591+686
2025141,869+278

Age, 2020–2024

The median age is 40.3 ±0.3: for men 39.0 ±0.5 and for women 41.3 ±0.3. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Rock Island County by age, ACS 2020–2024
AgePeopleShare
Under 58,232 ±1825.8% ±0.1
5 to 1723,859 ±83016.7% ±0.6
18 to 2412,634 ±6528.9% ±0.5
25 to 4434,679 ±73924.3% ±0.5
45 to 6434,292 ±74124.0% ±0.5
65 and over29,061 ±99220.4% ±0.7

Income and poverty, 2020–2024

Median household income is $67,159 ±$1,869, and income per person $36,842 ±$864, in 2024 dollars. The median is $83,390 ±$362 in Illinois and $80,734 ±$166 in the United States.

Households by income

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Households in Rock Island County by income, ACS 2020–2024
Household incomeHouseholdsShare
Under $25,00010,773 ±81717.5% ±1.3
$25,000 to $49,99912,876 ±87820.9% ±1.4
$50,000 to $74,99910,401 ±68616.8% ±1.1
$75,000 to $99,9998,517 ±63913.8% ±1.0
$100,000 to $149,99910,497 ±78217.0% ±1.3
$150,000 to $199,9994,952 ±4198.0% ±0.7
$200,000 or more3,717 ±4126.0% ±0.7

Poverty by age

The poverty rate is the share of people whose family income is below the federal threshold for their family’s size, of everyone for whom the Bureau determines it (B17020).

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Poverty rate in Rock Island County by age, ACS 2020–2024
AgeBelow povertyRate
All ages21,292 ±1,47115.5% ±1.1
Under 187,443 ±76723.7% ±2.3
18 to 5910,131 ±83414.8% ±1.2
60 and over3,718 ±4679.9% ±1.2

Housing, 2020–2024

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Housing in Rock Island County, ACS 2020–2024
MeasureRock Island CountyIllinois
Housing units66,759 ±1305,457,452 ±471
Occupied92.5% ±0.892.3% ±0.1
Vacant7.5% ±0.87.7% ±0.1
Owner occupied69.7% ±1.267.1% ±0.3
Renter occupied30.3% ±1.232.9% ±0.2
Median home value$150,400 ±$3,354$263,300 ±$797
Median gross rent$889 ±$21$1,274 ±$5
Median year built1962 ±21971 ±2

Occupied and vacant are shares of all housing units; owner and renter occupied are shares of occupied units. Value and rent are medians in 2024 dollars.

Origin and place of birth, 2020–2024

Hispanic or Latino origin is not a race in the Census Bureau’s tables. Here the people of Hispanic origin, of any race, are one row, and everyone else is counted by race alone (B03002), so the rows add to the whole.

Hispanic origin and race

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People in Rock Island County by Hispanic origin and race, ACS 2020–2024
OriginPeopleShare
Hispanic or Latino20,305 ±014.2% ±<0.1
White alone, not Hispanic96,160 ±46567.4% ±0.3
Black alone, not Hispanic15,568 ±71610.9% ±0.5
Asian alone, not Hispanic3,770 ±2992.6% ±0.2
American Indian and Alaska Native alone, not Hispanic92 ±420.1% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic0 to 1030% to 0.1%
Some other race alone, not Hispanic195 to 8530.1% to 0.6%
Two or more races, not Hispanic6,289 ±8724.4% ±0.6

A range (the estimate less and plus its margin) where the Bureau's estimate is too uncertain to state as one number: a coefficient of variation over 30%.

Place of birth and citizenship

“Born a citizen outside the states” counts people born in Puerto Rico, the island areas, or abroad to American parents. Naturalized citizens and those who are not citizens together make up the people born abroad (B05002).

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People in Rock Island County by place of birth and citizenship, ACS 2020–2024
BornPeopleShare
Born in the state91,146 ±1,45563.8% ±1.0
Born in another state37,929 ±1,43026.6% ±1.0
Born a citizen outside the states1,288 ±3160.9% ±0.2
Born abroad12,394 ±8708.7% ±0.6
Naturalized citizens5,794 ±6684.1% ±0.5
Not citizens6,600 ±7894.6% ±0.6

Rock Island County among the counties of Illinois

15th of 102 by population, July 2025. Every one is listed on the Illinois page.

Counties of Illinois near Rock Island County in population, July 2025
CountyJuly 2025Change since 2020
Champaign County209,972+1.8%
Sangamon County194,170−1.0%
Peoria County178,553−1.6%
McLean County171,419+0.1%
Kendall County145,470+9.9%
Rock Island County141,869−1.7%
Tazewell County130,049−1.0%
LaSalle County107,773−1.5%
Kankakee County105,525−1.7%
DeKalb County101,835+1.5%
Macon County99,300−4.3%

Elsewhere on the site

Rankings this appears in

Sources

Compiled automatically from Census Bureau population estimates — counties and Puerto Rico municipios, with components of change and American Community Survey 5-year estimates — table-based Summary File by a checked SQL query · Editor: Kian O'Connor · How this site is built

Data retrieved