St. Clair County, Illinois Population 2020

St. Clair County, Illinois's estimated population is 258,325 with a growth rate of -0.53% in the past year according to the most recent United States census data. St. Clair County, Illinois is the 9th largest county in Illinois.

Year Population Growth Growth Rate
2020258,325-1,367-0.53%
2019259,692-1,367-0.52%
2018261,059-1,367-0.52%
2017262,426-676-0.26%
2016263,102-1,703-0.64%
2015264,805-1,117-0.42%
2014265,922-883-0.33%
2013266,805-1,841-0.69%
2012268,646-1,360-0.50%
2011270,006-336-0.12%
2010270,3427,4902.85%
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%
18001,3550.00%
2020 Growth Rate
-0.53%
County Website
Founded
1790
County Seat

St. Clair County, Illinois Population Growth

Population by Race

Race Population Percentage
White168,90364.11%
Black or African American79,35130.12%
Two or More Races7,2582.75%
Asian3,7511.42%
Some Other Race3,6941.40%
American Indian and Alaska Native4440.17%
Native Hawaiian and Other Pacific Islander620.02%

St. Clair County, Illinois Population Pyramid 2020

St. Clair County, Illinois Median Age

38.3


Total

36.6


Male

39.9


Female

St. Clair County, Illinois Adults

There are 201,008 adults, (38,873 of whom are seniors) in St. Clair County, Illinois.

St. Clair County, Illinois Age Dependency

62.5

Age Dependency Ratio

24

Old Age Dependency Ratio

38.5

Child Dependency Ratio

St. Clair County, Illinois Sex Ratio

Female

136,226

51.71%

Male

127,237

48.29%

St. Clair County, Illinois Households and Families

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

St. Clair County, Illinois Household Types

Type Owner Renter
Married84%16%
Male69.1%30.9%
All64.9%35.1%
Non Family52.3%47.7%
Female39.7%60.3%

64.9%

Rate of Home Ownership

Type Count Average Size Owned
All103,0632.5264.9
Married45,0433.1784
Non Family37,7231.1852.3
Female15,7993.6239.7
Male4,4983.3669.1

3.21

Average Family Size

2.52

Average Household Size

5.6%

Unmarried (Opposite Sex)

0.3%

Unmarried (Same Sex)

St. Clair County, Illinois Education

Education Attained Count Percentage
Less Than 9th Grade4,4912.52%
9th to 12th Grade11,9056.68%
High School Graduate50,92828.59%
Some College42,18723.68%
Associates Degree19,96511.21%
Bachelors Degree28,47115.98%
Graduate Degree20,19211.33%

St. Clair County, Illinois Educational Attainment by Race

Name Total High School Bachelors
White118,484111,53237,473
Black48,78541,2537,935
Hispanic5,5484,1981,248
Asian2,6782,2531,193
Multiple Races2,5762,421837
Other Race2,1001,442316
Native American36832248
Islander333310

The highest rate of high school graduation is among islander people with a rate of 100.00%.

The highest rate of bachelors degrees is among asian people with a rate of 44.55%.

Name Average Male Female
Overall$38,047$45,099$31,673
Less Than High School$20,733$23,028$14,380
High School Grad$29,190$35,063$23,557
Some College$35,020$42,083$29,106
Bachelors Degree$53,164$65,746$41,817
Graduate Degree$66,591$86,000$56,263

$38,047

Average Earnings

$45,099

Average Male

$31,673

Average Female

St. Clair County, Illinois Language

St. Clair County, Illinois Language by Age

St. Clair County, Illinois Language

94.92% of St. Clair County, Illinois residents speak only English, while 5.08% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 2.62% of the population.

St. Clair County, Illinois Poverty

St. Clair County, Illinois Poverty by Race

Name Total In Poverty Poverty Rate
Black78,18525,76632.96%
White160,41912,7177.93%
Hispanic10,2362,52224.64%
Other3,6691,28435.00%
Multiple7,0911,25417.68%
Asian3,7182376.37%
Native44413430.18%
Islander6246.45%

16.35%

Overall Poverty Rate

14.39%

Male Poverty Rate

18.18%

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 35.00% below the poverty level.

The race least likely to be in poverty in St. Clair County, Illinois is Asian, with 6.37% below the poverty level.

The poverty rate among those that worked full-time for the past 12 months was 2.92%. Among those working part-time, it was 17.42%, and for those that did not work, the poverty rate was 24.56%.

Name Poverty
Less Than High School31.73%
High School16.75%
Some College11.26%
Bachelors or Greater3.81%
Name Poverty
Female Unemployed37.98%
Male Unemployed30.58%
Female Employed9.80%
Male Employed4.05%

St. Clair County, Illinois Income

St. Clair County, Illinois Income by Household Type

Name Median Mean
Households$53,681$73,185
Families$72,482$89,901
Married Families$92,755$110,279
Non Families$30,311$41,148

St. Clair County, Illinois Marital Status

St. Clair County, Illinois Marital Status

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

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

St. Clair County, Illinois Veterans

24,799

Number of Veterans

21,497

Male Veterans

3,302

Female Veterans

War Veterans
First Gulf War8,535
Vietnam8,149
Second Gulf War6,852
Korea1,473
World War II781
Age Group Veterans
35 to 547,461
65 to 745,513
55 to 645,492
75+3,890
18 to 342,443
Name Veterans % of Total
White18,50814.07%
Black5,1469.01%
Hispanic65610.19%
2 or More59418.61%
Other25510.57%
Asian1936.48%
Indian9322.30%
Hawaiian1016.67%

$St. Clair County, Illinois Veterans by Education

6.55%

Veteran Poverty Rate

23.34%

Veteran Disability Rate

St. Clair County, Illinois Employment Status

62.9%

Labor Force Participation

56.9%

Employment Rate

7.1%

Unemployment Rate

St. Clair County, Illinois Place of Birth

Origin of Non-Citizens

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

Origin of Naturalized Citizens

59.70%

Born in Illinois

97.08%

Native Born

2.92%

Foreign Born

1.52%

Non Citizen

Place of Birth

97.08% of St. Clair County, Illinois residents were born in the United States, with 59.70% having been born in Illinois. 1.52% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Asia.

  1. US Census City/Town Population estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. Population of States and Counties of the United States: 1790 - 1990