St. Clair County: Demographics & People

Census counts 9,587 people in St. Clair County. Median age 46.1 years. (6.9y older than Missouri). Population is 2% Hispanic or Latino and 1% Black. County is gaining 586 residents per year (2022-2023). County health: 39% adult obesity, 25% smoke.

Population & Trend

Current population 9,587; figures track the most recent Census ACS 5-year estimates.

Population9,587 people
Total Town Population2,825 people

Age Distribution

Median age 46.1y is 7.2 years older than the U.S. median (38.9y).

Age Summary · Total Pop9,587
Age Summary · Under 182,038
Age Summary · 18 To 341,545.0×
Age Summary · 35 To 643,547.0×
Age Summary · 65 Plus2,457
Age Summary · Pct Under 1821.3%
Age Summary · Pct 18 To 3416.1%
Age Summary · Pct 35 To 6437.0%
Median age46.1 years (vs Missouri 39.2y)

Sources: Census ACS 5-Year 2024 — county-level query  ·  Refreshed 2026-04-28

Race, Ethnicity & Diversity

Of 9,587 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups).

Census Demographics · Total Population9,587 people
White residents8,960
Black residents77
Asian residents24
Census Demographics · Aian16
Census Demographics · Other Race71
Census Demographics · Two Or More Races439
Hispanic or Latino residents213
Diversity Index12.4%
Asian population0.2%
Black population0.8%
Hispanic or Latino population2.2%

Sources: Census ACS 5-Year 2024 — county-level query  ·  Refreshed 2026-04-28

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS).

Census Citizenship · Total9,587
Census Citizenship · Native9,475
Residents born in this state6,564
Residents born in another state2,866
Census Citizenship · Foreign Born826
Census Citizenship · Naturalized636
Census Citizenship · Non Citizen45
Foreign-born residents8.6%

Sources: Census ACS 5-Year 2024 — county-level query  ·  Refreshed 2026-04-28

Residential Stability & Migration

How long residents have lived here and where they came from. The surrounding county is gaining 586 residents per year on net (IRS migration data).

Migration · People moving in (annual)8,649
Migration · People moving out (annual)8,063
Migration · Net migration (in − out)586
Migration · Population growingYes
Migration · Year2022-2023

Sources: IRS SOI Migration 2022-2023

Disability

Census ACS measures self-reported functional limitations — vision, hearing, mobility, cognitive, self-care, or independent-living. The U.S. baseline disability rate is about 12–13%; rates trend higher with median age.

Census Disability · Total Pop9,385
With Disability1,958
Pct With Disability20.9%

Sources: Census ACS 5-Year 2024 — county-level query  ·  Refreshed 2026-04-28

Group Quarters

Group quarters are non-household living arrangements counted by the Census — college dormitories, nursing homes, military barracks, group homes, correctional facilities, and similar institutional or shared housing. 0 residents live in group quarters.

Census Group Quarters · Total187

Sources: Census ACS 5-Year 2024 — county-level query  ·  Refreshed 2026-04-28

Other

Census Mobility · Total9,536
Census Mobility · Same House8,469
Census Mobility · Same County308
Census Mobility · Diff County Same State536
Census Mobility · Diff State211
Census Mobility · From Abroad12
Census Mobility · Moved Total1,067
Census Mobility · Pct Moved In Year11.2%
Pct White93.5%

Sources: Census ACS 5-Year 2024 — county-level query  ·  Refreshed 2026-04-28