Demographics of Clinton County, Illinois

Clinton County, Illinois had 37,128 people on July 1, 2025, by the Census Bureau’s estimate: +213 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.

Clinton County, in four figures

37,128
Population: July 1, 2025, Vintage 2025 estimate.; +0.6%
Change since July 2020: +213 people.; 41.5 ±0.7
Median age: ACS 2020–⁠2024.; $86,588 ±$4,464
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.

Clinton County, Illinois's population grew 0.6% from July 2020 to July 2025, against +3.1% nationally

The July 1 estimate of Clinton 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).

U.S. Census Bureau — Census Bureau population estimates — counties and Puerto Rico municipios, with components of change

About this chart

The figures

Clinton County, Illinois's population grew 0.6% from July 2020 to July 2025, against +3.1% nationally. The July 1 estimate of Clinton 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 1	Population	Index	United States
2020	36,915	100.0	100.0
2021	36,915	100.0	100.2
2022	37,051	100.4	100.7
2023	36,938	100.1	101.6
2024	37,088	100.5	102.5
2025	37,128	100.6	103.1

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Population of Clinton County, Illinois on July 1 of each year, Vintage 2025
July 1	Population	Change	Births less deaths	From abroad	From elsewhere in the country
2020	36,915	+11	+1	0	+2
2021	36,915	0	+1	+15	−50
2022	37,051	+136	+37	+44	+83
2023	36,938	−113	+14	+81	−205
2024	37,088	+150	−1	+37	+118
2025	37,128	+40	−17	+18	+37

Age, 2020–2024

The median age is 41.5 ±0.7: for men 40.3 ±0.8 and for women 42.8 ±0.4. Shares are of everyone the survey counts, in the Bureau’s sex-by-age table (B01001).

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People in Clinton County by age, ACS 2020–2024
Age	People	Share	Illinois	United States
Under 5	2,085 ±66	5.6% ±0.2	5.4% ±<0.1	5.6% ±<0.1
5 to 17	5,895 ±325	16.0% ±0.9	16.4% ±0.1	16.3% ±<0.1
18 to 24	2,549 ±229	6.9% ±0.6	9.1% ±<0.1	9.1% ±<0.1
25 to 44	9,515 ±384	25.7% ±1.0	26.9% ±0.1	26.9% ±<0.1
45 to 64	9,955 ±370	26.9% ±1.0	25.2% ±0.1	24.8% ±<0.1
65 and over	6,955 ±379	18.8% ±1.0	17.0% ±0.1	17.2% ±<0.1

Income and poverty, 2020–2024

Median household income is $86,588 ±$4,464, and income per person $42,658 ±$2,257, 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 Clinton County by income, ACS 2020–2024
Household income	Households	Share	Illinois	United States
Under $25,000	1,569 ±207	10.8% ±1.4	14.6% ±0.1	14.6% ±<0.1
$25,000 to $49,999	2,592 ±297	17.8% ±2.0	16.0% ±0.2	16.7% ±<0.1
$50,000 to $74,999	2,196 ±278	15.1% ±1.9	14.8% ±0.1	15.5% ±<0.1
$75,000 to $99,999	2,012 ±290	13.8% ±2.0	12.6% ±0.1	12.6% ±<0.1
$100,000 to $149,999	3,090 ±328	21.2% ±2.2	18.0% ±0.2	17.5% ±<0.1
$150,000 to $199,999	1,799 ±216	12.3% ±1.5	10.1% ±0.1	9.6% ±<0.1
$200,000 or more	1,312 ±223	9.0% ±1.5	13.8% ±0.1	13.4% ±0.1

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 Clinton County by age, ACS 2020–2024
Age	Below poverty	Rate	Illinois	United States
All ages	2,570 ±427	7.4% ±1.2	11.8% ±0.1	12.5% ±0.1
Under 18	646 ±184	8.3% ±2.3	15.1% ±0.2	16.1% ±0.1
18 to 59	1,211 ±267	6.8% ±1.5	11.0% ±0.1	11.6% ±0.1
60 and over	713 ±163	7.7% ±1.7	10.6% ±0.1	11.0% ±<0.1

Housing, 2020–2024

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Housing in Clinton County, ACS 2020–2024
Measure	Clinton County	Illinois	United States
Housing units	15,765 ±92	5,457,452 ±471	143,775,355 ±10,234
Occupied	92.4% ±1.5	92.3% ±0.1	89.9% ±0.1
Vacant	7.6% ±1.6	7.7% ±0.1	10.1% ±0.1
Owner occupied	80.3% ±1.4	67.1% ±0.3	65.2% ±0.3
Renter occupied	19.7% ±1.9	32.9% ±0.2	34.8% ±0.1
Median home value	$192,400 ±$6,257	$263,300 ±$797	$332,700 ±$236
Median gross rent	$912 ±$52	$1,274 ±$5	$1,413 ±$2
Median year built	1977 ±2	1971 ±2	1980 ±1

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 Clinton County by Hispanic origin and race, ACS 2020–2024
Origin	People	Share	Illinois	United States
Hispanic or Latino	1,512 ±0	4.1% ±<0.1	18.8% ±<0.1	19.3% ±<0.1
White alone, not Hispanic	33,295 ±92	90.1% ±0.2	58.1% ±<0.1	57.4% ±<0.1
Black alone, not Hispanic	1,147 ±110	3.1% ±0.3	13.3% ±<0.1	11.9% ±<0.1
Asian alone, not Hispanic	213 ±41	0.6% ±0.1	5.9% ±<0.1	5.9% ±<0.1
American Indian and Alaska Native alone, not Hispanic	14 to 84	< 0.1% to 0.2%	0.1% ±<0.1	0.5% ±<0.1
Native Hawaiian and Other Pacific Islander alone, not Hispanic	0 to 27	0% to 0.1%	< 0.1% ±<0.1	0.2% ±<0.1
Some other race alone, not Hispanic	0 to 22	0% to 0.1%	0.4% ±<0.1	0.6% ±<0.1
Two or more races, not Hispanic	728 ±162	2.0% ±0.4	3.4% ±0.1	4.3% ±<0.1

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 Clinton County by place of birth and citizenship, ACS 2020–2024
Born	People	Share	Illinois	United States
Born in the state	29,757 ±481	80.5% ±1.3	66.5% ±0.1	57.3% ±<0.1
Born in another state	5,965 ±443	16.1% ±1.2	17.5% ±0.1	26.9% ±<0.1
Born a citizen outside the states	364 ±125	1.0% ±0.3	1.3% ±<0.1	1.7% ±<0.1
Born abroad	868 ±155	2.3% ±0.4	14.7% ±0.1	14.1% ±<0.1
Naturalized citizens	357 ±110	1.0% ±0.3	7.7% ±0.1	7.4% ±<0.1
Not citizens	511 ±156	1.4% ±0.4	7.0% ±0.1	6.8% ±<0.1

Clinton County among the counties of Illinois

35th of 102 by population, July 2025. Every one is listed on the Illinois page.

Counties of Illinois near Clinton County in population, July 2025
County	July 2025	Change since 2020
Knox County	47,767	−4.1%
Coles County	46,607	−1.0%
Macoupin County	43,748	−2.6%
Stephenson County	43,220	−3.0%
Woodford County	38,111	−0.8%
Clinton County	37,128	+0.6%
Franklin County	36,916	−2.1%
Marion County	36,382	−3.4%
Jefferson County	36,147	−2.3%
Livingston County	35,057	−2.1%
Monroe County	34,840	−0.3%

Elsewhere on the site

Sources

Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026
American Community Survey 5-year estimates — table-based Summary File · U.S. Government work

Data retrieved September 25, 2026