St. Clair County: Demographics & People
Census counts 160,221 people in St. Clair County. Median age 44.5 years. (4.2y older than Michigan). Population is 4% Hispanic or Latino and 2% Black. County is gaining 1,610 residents per year (2022-2023). County health: 36% adult obesity, 20% smoke.
Population & Trend
Current population 160,221; figures track the most recent Census ACS 5-year estimates.
| Population | 160,221 people |
|---|---|
| Total Town Population | 63,133 people |
Age Distribution
Median age 44.5y is 5.6 years older than the U.S. median (38.9y).
| Age Summary · Total Pop | 160,221 |
|---|---|
| Age Summary · Under 18 | 32,478 |
| Age Summary · 18 To 34 | 30,430.0× |
| Age Summary · 35 To 64 | 64,664.0× |
| Age Summary · 65 Plus | 32,649 |
| Age Summary · Pct Under 18 | 20.3% |
| Age Summary · Pct 18 To 34 | 19.0% |
| Age Summary · Pct 35 To 64 | 40.4% |
| Median age | 44.5 years (vs Michigan 40.3y) |
Sources: Census ACS 5-Year 2024 — county-level query · Refreshed 2026-04-28
Race, Ethnicity & Diversity
Of 160,221 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups).
| Census Demographics · Total Population | 160,221 people |
|---|---|
| White residents | 146,136 |
| Black residents | 3,491 |
| Asian residents | 865 |
| Census Demographics · Aian | 271 |
| Census Demographics · Nhpi | 15 |
| Census Demographics · Other Race | 1,746 |
| Census Demographics · Two Or More Races | 7,697 |
| Diversity Index | 16.5% |
| Asian population | 0.5% |
| Black population | 2.2% |
| Hispanic or Latino population | 3.7% |
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 · Total | 160,221 |
|---|---|
| Census Citizenship · Native | 156,981 |
| Residents born in this state | 140,218 |
| Residents born in another state | 15,518 |
| Census Citizenship · Foreign Born | 4,958 |
| Census Citizenship · Naturalized | 2,600 |
| Census Citizenship · Non Citizen | 1,245 |
| Foreign-born residents | 3.1% |
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 1,610 residents per year on net (IRS migration data).
| Migration · People moving in (annual) | 147,763 |
|---|---|
| Migration · People moving out (annual) | 146,153 |
| Migration · Net migration (in − out) | 1,610 |
| Migration · Population growing | Yes |
| Migration · Year | 2022-2023 |
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 Pop | 159,030 |
|---|---|
| With Disability | 26,874 |
| Pct With Disability | 16.9% |
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 · Total | 1,454 |
|---|
Sources: Census ACS 5-Year 2024 — county-level query · Refreshed 2026-04-28
Other
| Census Mobility · Total | 158,496 |
|---|---|
| Census Mobility · Same House | 143,479 |
| Census Mobility · Same County | 9,931 |
| Census Mobility · Diff County Same State | 3,680 |
| Census Mobility · Diff State | 1,075 |
| Census Mobility · From Abroad | 331 |
| Census Mobility · Moved Total | 15,017 |
| Census Mobility · Pct Moved In Year | 9.5% |
| Pct White | 91.2% |
Sources: Census ACS 5-Year 2024 — county-level query · Refreshed 2026-04-28