St. Clair County, Illinois Population 2024

249,771

St. Clair County, Illinois's estimated 2024 population is 249,771 with a growth rate of -0.5% in the past year according to the most recent United States census data. St. Clair County, Illinois is the 9th largest county in Illinois. The 2010 population was 270,368 and has seen a growth of -7.62% since that time.

Note: data after 2022 is projected based on recent change
Year
Population
Growth
Change
2029243,536-1,247-0.51%
2028244,783-1,247-0.51%
2027246,030-1,247-0.5%
2026247,277-1,247-0.5%
2025248,524-1,247-0.5%
2024249,771-1,247-0.5%
2023251,018-1,247-0.49%
2022252,265-2,693-1.06%
2021254,958-1,886-0.73%
2020256,844-3,045-1.17%
2019259,889-1,742-0.67%
2018261,631-1,250-0.48%
2017262,881-601-0.23%
2016263,482-1,526-0.58%
2015265,008-1,053-0.4%
2014266,061-873-0.33%
2013266,934-1,814-0.67%
2012268,748-1,349-0.5%
2011270,097-271-0.1%
2010270,36800%
1990262,852-4,679-1.75%
1980267,531-17,645-6.19%
1970285,17622,6678.63%
1960262,50956,51427.43%
1950205,99539,09623.42%
1940166,8999,1245.78%
1930157,77521,25515.57%
1920136,52016,65013.89%
1910119,87033,18538.28%
190086,68520,11430.21%
189066,5714,7657.71%
188061,80610,73821.03%
187051,06813,37435.48%
186037,69417,51486.79%
185020,1806,54948.04%
184013,6316,55392.58%
18307,0781,82534.74%
18205,2532464.91%
18105,0073,652269.52%
18001,355-242,181-99.44%
2024 Growth Rate
-0.5% (-1,247)
County Website
St. Clair County
County Seat
Belleville
2020 Population
256,844
Area
658 mi²
Density
380 people/mi²
Growth Since 2020
-2.75% (-7,073)
Founded
1790

Population by Race

Race
Population
Percentage (of total)
White158,89161.88%
Black or African American72,69228.31%
Two or more races16,0996.27%
Other race4,0981.6%
Asian4,0221.57%
Native American9170.36%
Native Hawaiian or Pacific Islander720.03%

White

Black or African American

Two or more races

Other race

Asian

Native American

Native Hawaiian or Pacific Islander

St. Clair County, Illinois Population by Race

St. Clair County, Illinois Population Pyramid 2024

St. Clair County, Illinois Median Age

39.4

Total

38

Male

40.7

Female

St. Clair County, Illinois Adults

There are 197,075 adults, (42,018 of whom are seniors) in St. Clair County, Illinois.

St. Clair County, Illinois Age Dependency

65.6

Age Dependency Ratio

27.1

Old Age Dependency Ratio

38.5

Child Dependency Ratio

St. Clair County, Illinois Sex Ratio

Female131,92751.38%
Male124,86448.62%

St. Clair County, Illinois Population by Age

St. Clair County, Illinois Renter vs Owner Occupied by Household Type

Household Type
Count
Average Size
Owner
Renter
All100,7012.5167.932.1
Married44,8173.1485.314.7
Non Family36,4881.1755.144.9
Female14,9153.6247.752.3
Male4,4813.3465.734.3

3.17

Average Family Size

2.51

Average Household Size

67.9%

Rate of Home Ownership

Married

Male

Female

NonFamily

owner

renter

St. Clair County, Illinois Households and Families

Male

Female

Education Attained
Count
Percentage
9th to 12th Grade9,4425.39%
Associates Degree19,71911.25%
Bachelors Degree31,09717.74%
Graduate Degree22,14112.63%
High School Graduate46,50726.54%
Less Than 9th Grade4,1732.38%
Some College42,16824.06%

Less Than 9th Grade

9th to 12th Grade

High School Graduate

Some College

Associates Degree

Bachelors Degree

Graduate Degree

St. Clair County, Illinois Educational Attainment by Sex (over 25)

St. Clair County, Illinois Educational Attainment by Race

High School Graduation Rate

Bachelors Rate

Race
Total
High School
Bachelors
White113,216107,79138,864
Black46,87840,7628,987
2+ Races7,0086,5052,470
Hispanic6,1184,7981,656
Asian2,8182,4941,529
Other Race2,2381,612592
Native American620540199
Islander29290

The highest rate of high school graduation is among islander people with a rate of 100%.

The highest rate of bachelors degrees is among asian people with a rate of 54.26%.

St. Clair County, Illinois Educational Attainment by Race

All

Male

Female

Name
Average
Male
Female
Bachelors Degree$61,341$74,815$54,660
Graduate Degree$77,430$92,841$62,198
High School Graduate$33,263$41,034$26,670
Less Than 9th Grade$25,501$29,654$23,392
Overall$46,245$56,116$38,295
Some College$42,002$55,850$33,965

$46,245

Average Earnings

$56,116

Average Male

$38,295

Average Female

St. Clair County, Illinois Earnings by Educational Attainment

St. Clair County, Illinois Language by Age

Only English

Spanish

Other Indo-European Languages

Asian and Pacific Island Languages

Other Languages

St. Clair County, Illinois Language

95.05% of St. Clair County, Illinois residents speak only English, while 4.95% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 2.45% of the population.

St. Clair County, Illinois Language

St. Clair County, Illinois Poverty by Race

rate

Name
Total
In Poverty
Poverty Rate
Black71,18718,89126.54%
White151,49911,2797.44%
Multiple15,7892,46915.64%
Hispanic11,3782,32720.45%
Other4,0801,05825.93%
Asian3,9853789.49%
Native88917619.8%

13.8%

Overall Poverty Rate

12.17%

Male Poverty Rate

15.33%

Female Poverty Rate

Poverty in St. Clair County, Illinois

The race most likely to be in poverty in St. Clair County, Illinois is Black, with 26.54% below the poverty level.

The race least likely to be in poverty in St. Clair County, Illinois is White, with 7.44% below the poverty level.

The poverty rate among those that worked full-time for the past 12 months was 2.04%. Among those working part-time, it was 16.35%, and for those that did not work, the poverty rate was 21.49%.

St. Clair County, Illinois Poverty

rate

Rate
Poverty
Less Than 9th Grade28.05%
High School16.03%
Some College9.61%
Bachelors or Greater3.96%

St. Clair County, Illinois Poverty Rate by Education

rate

Rate
Poverty
Male Unemployed27.96%
Female Unemployed25.84%
Female Employed8.76%
Male Employed4.22%

St. Clair County, Illinois Poverty Rate by Employment Status and Sex

St. Clair County, Illinois Income by Household Type

Households

Families

MarriedFamilies

NonFamilies

Name
Median
Mean
Families$88,951$108,281
Households$68,915$89,002
Married Families$110,868$129,923
Non Families$38,842$51,497

mean

median

Income by Household Type

St. Clair County, Illinois Marital Status

Married

Widowed

Divorced

Separated

NeverMarried

Marriage Rates

45.7%

Overall Marriage Rate

48.1%

Male Marriage Rate

43.4%

Female Marriage Rate

St. Clair County, Illinois Married by Age and Sex

male

female

St. Clair County, Illinois Marriage

The age group where males are most likely to be married is Over 65, while the female age group most likely to be married is 35-44.

St. Clair County, Illinois Marital Status by Race

Married

Widowed

Divorced

Separated

NeverMarried

St. Clair County, Illinois Marital Status

Second Gulf War

First Gulf War

Vietnam

Korea

World War II

23,588

Number of Veterans

20,687

Male Veterans

2,901

Female Veterans

War
Veterans
First Gulf War9,236
Second Gulf War8,470
Vietnam6,561
Korea1,043
World War II386

St. Clair County, Illinois Veterans by War

count

Age Group
Veterans
35 to 547,470
65 to 745,392
55 to 645,072
75+3,727
18 to 341,927

St. Clair County, Illinois Veterans by Age

count

Name
Veterans
% of Total
White16,79113.44%
Black5,3509.93%
2+ Races96211.79%
Hispanic7099.97%
Other Race2499.11%
Asian2167.05%
Native American202.85%

St. Clair County, Illinois Veterans by Race

St. Clair County, Illinois Veterans by Education

Less Than 9th Grade

High School Graduate

Some College

Bachelors or Greater

6.81%

Veteran Poverty Rate

24.59%

Veteran Disability Rate

St. Clair County, Illinois Veterans by Education

LaborForceParticipation

64.2%

Labor Force Participation

58.9%

Employment Rate

5.7%

Unemployment Rate

St. Clair County, Illinois Employment by Age

LaborForceParticipation

St. Clair County, Illinois Employment by Race

LaborForceParticipation

St. Clair County, Illinois Employment by Education

Origin of Non-Citizens

Europe

Asia

Africa

Oceania

Latin America

North America

Non citizens include legal permanent residents (green card holders), international students, temporary workers, humanitarian migrants, and illegal immigrants.

Origin of Naturalized Citizens

Europe

Asia

Africa

Oceania

Latin America

North America

57.65%

Born in St. Clair County, Illinois

96.83%

Native Born

3.17%

Foreign Born

1.31%

Non Citizen

1.86%

Naturalized

Place of Birth

96.83% of St. Clair County, Illinois residents were born in the United States, with 57.65% having been born in Illinois. 1.31% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Asia.

St. Clair County, Illinois Place of Birth

Sources