St. Clair County, IL demographics:
population, income, and more

Total population
253,694
-0.4% year-over-year change
Median household income
$73,854/yr
5.2% year-over-year change
Housing units
115,630
0.2% year-over-year change

St. Clair County population

How many people live in St. Clair County

St. Clair County is home to 253,694 residents, according to the most recent Census data. Gender-wise, 48.5% of St. Clair County locals are male, and 51.5% are female.

Total population
253,694
-0.4% year-over-year change
Gender ratio
Male
48.5%
123,111
Female
51.5%
130,583
Value Percent YoY change
Male 123,111 48.5% -0.4%
Female 130,583 51.5% -0.5%
A higher population often means more rental variety and livelier areas. The gender balance—how many men live here compared to women—can reveal a lot about the community and the lifestyles of its residents. Use this info to get a sense of the area's pace and personality.

Age demographics

The median age in St. Clair County is 40, with the population distributed as follows: about 18.9% are children under 15, then 12.2% are in the 15 to 24 age group. Adults between 25 and 44 make up 26% of the population, while another 25.4% fall into the 45 to 64 bracket. Finally, around 17.4% are 65 or older.

Median age
39.9
Age breakdown
Under 15
18.9%
15 to 24
12.2%
25 to 44
26%
45 to 64
25.4%
Over 65
17.4%
Value Percent YoY change
Under 15 47,967 18.9% -1.9%
15 to 24 31,082 12.2% -0.3%
25 to 44 66,079 26% -0.3%
45 to 64 64,559 25.4% -1.8%
Over 65 44,007 17.4% 3.0%
The age composition helps you get insight into who lives in the area. A younger population might mean a more active, fast-paced vibe, while an older one could suggest a quieter, slower lifestyle. If there's a balanced makeup, you’re likely to find a variety of services, housing types, and community spaces that cater to different life stages.

Racial makeup

In St. Clair County, 95.1% of the population are US-born citizens, while 3.3% have gained naturalized citizenship. At the same time, 1.5% of residents are non-citizens. As for race, 60.1% of locals are Caucasian, 27.9% are African American and 1.6% have Asian roots. There’s also a share of 7.8% that includes residents with two or more races.

Citizenship
U.S.-born citizens
95.1%
Non-U.S.-born citizens
3.3%
Non-citizens
1.5%
Value Percent YoY change
U.S.-born citizens 241,372 95.1% -0.5%
Non-U.S.-born citizens 8,481 3.3% -1.6%
Non-citizens 3,841 1.5% 8.8%
Racial breakdown
White
60.1%
Black or African American
27.9%
American Indian and Alaska Native
0.2%
Asian
1.6%
Native Hawaiian and other Pacific Islander
0%
Two or more races
7.8%
Other
2.2%
Value Percent
White 152,523 60.1%
Black or African American 70,726 27.9%
American Indian and Alaska Native 642 0.2%
Asian 4,174 1.6%
Native Hawaiian and other Pacific Islander 58 0%
Two or more races 19,866 7.8%
Other 5,705 2.2%

Households in St. Clair County

A peek inside St. Clair County households

St. Clair County has 100,846 households, with an average of 2 members in each. Of these, 63% are families, while the remaining 37% are made up of individuals living alone or with non-relatives, such as roommates.

Households stats

Total households
100,846
-0.4% year-over-year change
Average people per household
2
Non-family households
37,272
Family households
63,574
Value Percent YoY change
Non-family households 37,272 37% 0.7%
Family households 63,574 63% -1.0%
The mix between family and non-family households gives a glimpse into daily life. A higher percentage of families might mean more parks and schools, while more non-family setups can mean flexible housing and diverse living styles. For renters, this can signal what kinds of homes are common and can help you figure out if the area matches your lifestyle.

Housing in St. Clair County

The housing landscape of St. Clair County

St. Clair County's housing consists of 115,630 units, with 72.1% being detached single-family homes ideal for those wanting space. Attached options, including duplexes and townhouses, make up 5.2% and offer a more compact, shared living style. Then there are the multifamily buildings in the area, and for those seeking flexibility, non-traditional options like mobile homes account for 4.4% of the housing landscape.

Housing units
115,630
0.2% year-over-year change
Housing types
Value Percent
1 unit, detached 83,398 72.1%
1 unit, attached 5,984 5.2%
2 units 3,826 3.3%
3 or 4 units 5,130 4.4%
5 to 9 units 6,148 5.3%
10 to 19 units 2,669 2.3%
20 to 49 units 1,178 1%
50 or more units 2,155 1.9%
Mobile home 5,114 4.4%
Boat, RV, van, etc. 28 0%
Homes built since 2020
1,040
44.2% year-over-year change

The age of buildings in St. Clair County

In St. Clair County, the median construction year is 1975. About 13.5% of homes were built before the 1940s, with another 5.7% going up by 1949. Most development happened in the second half of the 20th century. Then, 14.2% of homes were added from 2000 to 2009, 7.4% between 2010 and 2019, and 0.9% are part of the newest wave of development.

Construction year breakdown by decade
Value Percent YoY change
Built in 1939 or earlier 15,578 13.5% 0.9%
Built between 1940 and 1949 6,628 5.7% 4.0%
Built between 1950 and 1959 15,055 13% -6.1%
Built between 1960 and 1969 13,973 12.1% 2.7%
Built between 1970 and 1979 12,300 10.6% -0.7%
Built between 1980 and 1989 12,538 10.8% 0.3%
Built between 1990 and 1999 13,572 11.7% -5.5%
Built between 2000 and 2009 16,452 14.2% 3.6%
Built between 2010 and 2019 8,494 7.4% 5.5%
Built in 2020 or later 1,040 0.9% 44.2%
As a renter, knowing when homes were built helps you understand the potential condition and design of rental units. Newer builds may have more contemporary layouts, while older homes can offer character or larger lots, depending on the area.

St. Clair County occupancy rates

Out of the 100,846 occupied housing units in St. Clair County, 68.4% are owner-occupied, while 31.6% are lived in by tenants. Meanwhile, 12.8% of all homes on the local market sit vacant.

Occupied housing units
100,846
-0.4% year-over-year change
Occupancy breakdown
Renter occupied
31,823
Owner occupied
69,023
Value Percent YoY
change
Renter occupied 31,823 31.6% -2.4%
Owner occupied 69,023 68.4% 0.5%
Unoccupied housing units
12.8%
Unoccupied housing units refer to homes that are currently without residents—whether they're waiting for renters or owners, used seasonally, or simply unclaimed. A higher share of empty homes may mean more housing availability, while a low number can reflect a tighter market with more competition. This, along with the renter-vs.-owner mix, helps paint a clearer picture of what types of housing and services are likely to be available in the area.

St. Clair County housing costs

Housing costs in St. Clair County come to a median of $1,129 per month, while tenants specifically pay a median gross rent of $1,090.

Median housing costs per month
$1,129/month
This figure sums up typical monthly housing costs for all households in the area. If you own, it includes mortgage payments in addition to property taxes, insurance and HOA fees. If you rent, it accounts for rent plus extras like utilities. It’s useful for seeing how local living expenses stack up compared to other places.
Median gross rent in St. Clair County
$1,090/month
Gross rent gives a more complete look at what renters actually pay, including not just base rent, but also utilities and fees. It’s a key number for evaluating rental affordability in your area of interest and understanding how it compares to nearby locations.

Education in St. Clair County

St. Clair County education at a glance

About 33.4% of the population in St. Clair County went to high school, while 24.3% pursued college studies. Another 10.7% earned an associate degree and 17.1% hold a bachelor’s. Meanwhile, 12.4% went even further, earning a master’s or doctorate.

Education level
Value Percent YoY change
No high school 4,244 2.2% -8.3%
High school diploma 65,180 33.4% -1.3%
College diploma 47,366 24.3% -1.7%
Associate degree 20,842 10.7% 0.3%
Bachelor's degree 33,389 17.1% 2.4%
Graduate degree 24,260 12.4% 4.7%
A community’s education mix can offer insights into the local economy and housing market. Higher levels of education often align with more job opportunities and stable incomes, which can increase demand for homes and influence both rent prices and rental availability.

Income in St. Clair County

How much people earn in St. Clair County

The average annual household income in St. Clair County was $96,049 in 2024, the most recent annual data available, according to the U.S. Census Bureau. This marked a +3.4% change from the previous year. At the same time, the median income stood at $73,854, reflecting a +5.2% shift over the same period.

Average household income in St. Clair County
$96,049/year
3.5% year-over-year change
Median household income in St. Clair County
$73,854/year
5.2% year-over-year change

St. Clair County income by age

In St. Clair County, households led by residents aged 25 to 44 — usually in the early to mid stages of their careers — have a median income of $83,776. Those with someone between 45 and 64 in charge, often well established professionally, earn $89,916 overall. Younger households, where the main provider is under 25 and just starting out, report a median income of $36,291, while those led by someone over 65, many of whom may be retired, have about $54,949 in earnings. Overall, 86.4% of the locals in this community live above the poverty line.

Income breakdown by age
Value YoY change
Under 25 $36,291 1.4%
25 - 44 $83,776 8.9%
45 - 64 $89,916 6.6%
Over 65 $54,949 4.3%
Above poverty level
212,226
Below poverty level
33,299
Value Percent YoY
change
Above poverty level 212,226 86.4% -0.7%
Below poverty level 33,299 13.6% -0.3%

Employment in St. Clair County

Workforce and job types in St. Clair County

The job market in St. Clair County is powered by 116,728 working residents, spread across a range of industries and roles. 78.2% of the working population are employed in professional or administrative positions, while 21.8% are in hands-on or service-based jobs. Also, 6.8% run their own businesses, 65.7% are employed by private companies, and 17.9% work in the public sector.

Workforce demographics

Working population
116,728
-0.5% year-over-year change
White collar
91,241
Blue collar
25,487
Value Percent YoY change
White collar 91,241 78.2% 0.0%
Blue collar 25,487 21.8% -2.1%
Employer type
Self employees
6.8%
Private companies
65.7%
Governmental workers
17.9%
Not for profit companies
9.6%
Value Percent YoY change
Self employees 7,997 6.8% -4.8%
Private companies 76,691 65.7% -2.3%
Governmental workers 20,880 17.9% 5.0%
Not for profit companies 11,160 9.6% 6.2%
Unemployment rate
6.0%
4.7% year-over-year change

Available workforce

The unemployment rate in St. Clair County stands at 6%, representing the share of the workforce currently without a job and actively looking for one.

For renters, the unemployment rate helps paint a picture of job security and financial stability in the area. Rates around 4% to 5% are considered typical. A lower-than-average rate might suggest strong job prospects and a thriving local economy, while a higher rate could hint at fewer opportunities—both useful to consider when planning a move.

Transportation in St. Clair County

How people get around in St. Clair County

In St. Clair County, the average commute time is 24 minutes. Commuting methods vary: 83.5% of residents travel by personal vehicle and 1.5% prefer to walk, while the remaining share relies on public transit or on two wheelers to get from A to B.

Commute time
24 min
-2.8% year-over-year change
Means of transportation
Value Percent YoY change
Car 98,397 83.5% -1.9%
Taxicab 39 0% 77.3%
Bus or trolleybus 1,214 1% -18.1%
Subway or elevated 116 0.1% N/A
Railroad 138 0.1% -9.2%
Ferryboat 16 0% -38.5%
Motorcycle 20 0% -85.1%
Bicycle 152 0.1% -2.6%
Walk 1,720 1.5% -5.8%
Understanding how locals get to work can help you plan your own routine. High car usage might mean you’ll need a vehicle, while strong public transit or walkability could save you the hassle. Commute times also play a big role in quality of life—shorter trips can give you more time for the things you enjoy.

What is the median and average household income in St. Clair County by zipcode?

Zipcode Population Number of households Median income Average income
62201 4,921 2,065 $27,437 $46,901
62203 5,465 1,843 $42,111 $57,241
62204 4,055 1,710 $35,346 $42,696
62205 6,459 2,276 $45,672 $63,220
62206 12,959 4,620 $33,838 $51,434
62207 6,984 2,593 $29,845 $53,698
62208 16,821 7,336 $80,205 $91,282
62220 19,152 7,873 $65,952 $86,008
62221 29,875 12,151 $82,271 $100,303
62059 729 278 $30,673 $52,089

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FAQs about St. Clair County demographics 

What is the total population of St. Clair County?

St. Clair County has a total population of 253,694 residents, according to the latest release from the U.S. Census Bureau: the 2019-2023 American Community Survey (ACS) 5-year estimates. This figure changed by -0.4% compared to a year ago.

What is the gender ratio in St. Clair County?

The gender ratio in St. Clair County is as follows:
  • 48.5% males (123,111 residents)
  • 51.5% females (130,583 residents)

What is the median age in St. Clair County?

The median age in St. Clair County is 39.9.

What is the age distribution of the population in St. Clair County?

The age distribution in St. Clair County is as follows:
  • Under 15: 18.9% (47,967 residents)
  • Ages 15-24: 12.2% (31,082 residents)
  • Ages 25-44: 26% (66,079 residents)
  • Ages 45-64: 25.4% (64,559 residents)
  • Over 65: 17.4% (44,007 residents)

What is the racial and ethnic makeup of St. Clair County?

The racial and ethnic makeup of St. Clair County is as follows:
  • White: 60.1% (152,523 residents)
  • Black or African American: 27.9% (70,726 residents)
  • American Indian and Alaska Native: 0.2% (642 residents)
  • Asian: 1.6% (4,174 residents)
  • Native Hawaiian and Other Pacific Islander: 0% (58 residents)
  • Two or More Races: 7.8% (19,866 residents)
  • Other: 2.2% (5,705 residents)

What percentage of the population in St. Clair County are U.S.-born citizens?

U.S.-born citizens represent 95.1% of the population in St. Clair County.

How many housing units are there in St. Clair County?

There are 115,630 housing units in St. Clair County, reflecting a +0.2% change compared to the previous year, according to the latest data from the U.S. Census Bureau.

How many households are in St. Clair County and what is the average household size?

St. Clair County has a total of 100,846 households, with an average of 2 people in each.

What is the median household income in St. Clair County?

St. Clair County has a median household income of $73,854, representing a +5.2% shift from the previous year, according to the U.S. Census Bureau.

What is the employment rate and job market overview for St. Clair County?

The employment rate is 94% in St. Clair County, with a workforce of 116,728 residents. Here’s a detailed breakdown of the local job market:

Job types:
  • White-collar workers: 78.2% (91,241 residents)
  • Blue-collar workers: 21.8% (25,487 residents)

Places of employment:
  • Self-employed: 6.8% (7,997 residents)
  • Private companies: 65.7% (76,691 residents)
  • Governmental workers: 17.9% (20,880 residents)
  • Not-for-profit companies: 9.6% (11,160 residents)

Data source & methodology

The demographic data on this page was sourced from the latest U.S. Census Bureau release—the 2019–2023 American Community Survey (ACS) 5-year estimates.

The information, issued annually, is compiled and published by the Point2Homes Research Team as soon as new data becomes available.

No representation, guarantee, or warranty is made concerning the accuracy or completeness of modified or aggregated information for particular areas.

Page last updated: September 2025