St. Clair County, Missouri Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 89th-largest in Missouri
The population of St. Clair County, Missouri is 9,451 as of the 2023 American Community Survey, making it the 89th-largest county in Missouri. The median household income is $46,731, the median home value is $142,500, and the median age is 47.2.
The population of St. Clair County has grown 0.3% since 2010 (9,823 → 9,848), a +0.02% annualized rate.
9,451
Population
+0.02%
Annual growth
14
People / sq mi
$46,731
Median Income
$142,500
Median Home Value
St. Clair County covers 675 sq mi of land at 14.0 people per square mile.
About St. Clair County, MO
St. Clair County is defined demographically by education — 13.7% of adults hold a bachelor’s degree, below the national average. St. Clair County is a county in Missouri with a population of 9,451.
Incomes run on the lower side: a median household income of $46,731, below the US median of $78,538. The poverty rate is 12.8%, close to the national 12.4%. Median home value is $142,500, with typical rent around $607.
St. Clair County is among the least college-educated US counties, at 13.7% — below the national 35.0%. Remote work is below the national 14.0% at 6.6%, and the average commute runs about 29 minutes each way.
St. Clair County Population History (2010-2024)
The county of St. Clair County had a population of 9,823 in 2010 and 9,848 in 2024, a 0.3% growth over 14 years. The peak was 9,848 in 2024. Average annual growth rate: 0.02%.
9,848
Population (2024)
9,823
Population (2010)
9,848
Peak (2024)
0.02%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 9,823 |
| 2011 | 9,694 |
| 2012 | 9,533 |
| 2013 | 9,499 |
| 2014 | 9,446 |
| 2015 | 9,427 |
| 2016 | 9,310 |
| 2017 | 9,395 |
| 2018 | 9,431 |
| 2019 | 9,450 |
| 2020 | 9,346 |
| 2021 | 9,416 |
| 2022 | 9,581 |
| 2023 | 9,743 |
| 2024 | 9,848 |
Race & Ethnicity
| White | 93.6% |
| Black or African American | 0.8% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 2.1% |
| Two or More Races | 0.0% |
Age & Sex
47.2
Median Age
49.2%
Female
50.8%
Male
25.8%
Age 65+
Age Distribution
Children (under 15): 17.1% · Seniors (65+): 25.8%
Income & Poverty
| Median household income | $46,731$-22,189 vs state |
| Mean household income | $60,329 |
| Per-capita income | $26,548 |
| Poverty rate | 12.8%+4.4% vs state |
| Unemployment rate | 1.2% |
| Employment-to-population | 49.3% |
Top Industries by Employment
The largest employment sector in St. Clair County is professional & business services, accounting for 21.5% of workers.
How residents commute
0.1%
Drive alone
2.8%
Carpool
76.5%
Public transit
6.6%
Work from home
28.8 min
Avg commute
Housing
$142,500$-73,100 vs state
Median home value
$607
Median rent
75.7%
Homeownership rate
5,295
Total housing units
77.2%
Occupied
22.8%
Vacant
24.3%
Renter-occupied
Social & access
87.3%
With health insurance
89.5%
With broadband internet
29.4%
Foreign-born
9.3%
Veterans (18+)
22.8%
With a disability
98.5%
Speak language other than English at home
Education
87.9%
High School+
13.7%
Bachelor's+
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Part of Missouri
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County rankings
Frequently Asked Questions
St. Clair County, Missouri has a population of 9,451 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 89th-largest county in Missouri. Population density is 14 people per square mile.
The population of St. Clair County has grown 0.3% since 2010 (9,823 → 9,848), a +0.02% annualized rate.
The median household income in St. Clair County, Missouri is $46,731, with mean (average) household income of $60,329 and per-capita income of $26,548. 12.8% of residents live below the federal poverty level.
In St. Clair County, the largest racial and ethnic groups are White (93.6%), Hispanic or Latino (2.1%), Black or African American (0.8%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in St. Clair County, Missouri is 47.2 years. Residents are 49.2% female and 50.8% male.
The median home value in St. Clair County is $142,500 and median monthly rent is $607. 75.7% of occupied housing units are owner-occupied. The county has 5,295 total housing units, 22.8% of which are vacant.
The largest employment sector in St. Clair County, Missouri is professional, scientific, and management services, employing 21.5% of workers. The unemployment rate is 1.2%.
Kansas City is among the largest cities associated with St. Clair County, Missouri, with a population of 508,233.
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Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.