St. Clair County, Illinois Population 2023

253,602

St. Clair County, Illinois's estimated 2023 population is 253,602 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 270,056 and has seen a growth of -6.09% since that time.

Note: data after 2020 is projected based on recent growth

St. Clair County, Illinois Population 2023

Population by Race

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 2023

St. Clair County, Illinois Median Age

39.1

Total

37.4

Male

40.6

Female

St. Clair County, Illinois Adults

There are 199,862 adults, (41,097 of whom are seniors) in St. Clair County, Illinois.

St. Clair County, Illinois Age Dependency

64.5

Age Dependency Ratio

25.9

Old Age Dependency Ratio

38.6

Child Dependency Ratio

St. Clair County, Illinois Sex Ratio

Female135,05351.71%
Male126,13348.29%

St. Clair County, Illinois Population by Age

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

3.12

Average Family Size

2.46

Average Household Size

65.9%

Rate of Home Ownership

Married

Male

Female

NonFamily

owner

renter

St. Clair County, Illinois Households and Families

Male

Female

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

The highest rate of high school graduation is among white people with a rate of 83.21%.

The highest rate of bachelors degrees is among asian people with a rate of 46.16%.

St. Clair County, Illinois Educational Attainment by Race

All

Male

Female

$40,530

Average Earnings

$48,083

Average Male

$34,146

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

94.79% of St. Clair County, Illinois residents speak only English, while 5.21% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 2.76% of the population.

St. Clair County, Illinois Language

St. Clair County, Illinois Poverty by Race

rate

17.59%

Overall Poverty Rate

13.04%

Male Poverty Rate

15.7%

Female Poverty Rate

Poverty in St. Clair County, Illinois

The race most likely to be in poverty in St. Clair County, Illinois is Other, with 39.06% below the poverty level.

The race least likely to be in poverty in St. Clair County, Illinois is Native, with 6.2% below the poverty level.

The poverty rate among those that worked full-time for the past 12 months was 2.93%. Among those working part-time, it was 17.71%, and for those that did not work, the poverty rate was 21.52%.

St. Clair County, Illinois Poverty

St. Clair County, Illinois Poverty Rate by Education

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

St. Clair County, Illinois Income by Household Type

Households

Families

MarriedFamilies

NonFamilies

mean

median

Income by Household Type

St. Clair County, Illinois Marital Status

Married

Widowed

Divorced

Separated

NeverMarried

Marriage Rates

46.1%

Overall Marriage Rate

48.7%

Male Marriage Rate

43.8%

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 45-54.

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

24,717

Number of Veterans

21,596

Male Veterans

3,121

Female Veterans

St. Clair County, Illinois Veterans by War

St. Clair County, Illinois Veterans by Age

count

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

7.24%

Veteran Poverty Rate

25.16%

Veteran Disability Rate

St. Clair County, Illinois Veterans by Education

LaborForceParticipation

64.3%

Labor Force Participation

59.2%

Employment Rate

5.4%

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

59.66%

Born in St. Clair County, Illinois

98.35%

Native Born

3.12%

Foreign Born

1.51%

Non Citizen

1.61%

Naturalized

Place of Birth

98.35% of St. Clair County, Illinois residents were born in the United States, with 59.66% having been born in Illinois. 1.51% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Latin America.

St. Clair County, Illinois Place of Birth

Sources