St. Louis County: Demographics & People

995,569 people call St. Louis County home. Median age 40.3 years. (1.1y older than Missouri). Population is 24% Black and 5% Asian. County is losing 10,393 residents per year (2022-2023). County health: 34% adult obesity, 16% smoke.

Population & Trend

Current population 995,569; figures track the most recent Census ACS 5-year estimates.

Population995,569 people
Total Town Population845,394 people

Age Distribution

Median age 40.3y is 1.4 years older than the U.S. median (38.9y).

Age Summary · Total Pop995,569
Age Summary · Under 18218,904
Age Summary · 18 To 34209,948.0×
Age Summary · 35 To 64376,398.0×
Age Summary · 65 Plus190,319
Age Summary · Pct Under 1822.0%
Age Summary · Pct 18 To 3421.1%
Age Summary · Pct 35 To 6437.8%
Median age40.3 years (vs Missouri 39.2y)

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

Race, Ethnicity & Diversity

Of 995,569 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups).

Census Demographics · Total Population995,569 people
White residents618,307
Black residents240,070
Asian residents48,760
Census Demographics · Aian1,148
Census Demographics · Nhpi213
Census Demographics · Other Race17,813
Census Demographics · Two Or More Races69,258
Diversity Index54.9%
Asian population4.9%
Black population24.1%
Hispanic or Latino population3.9%

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 · Total995,569
Census Citizenship · Native912,426
Residents born in this state666,943
Residents born in another state237,733
Census Citizenship · Foreign Born68,436
Census Citizenship · Naturalized30,813
Census Citizenship · Non Citizen7,750
Foreign-born residents6.9%

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 losing 10,393 residents per year on net (IRS migration data).

Migration · People moving in (annual)897,558
Migration · People moving out (annual)907,951
Migration · Net migration (in − out)-10,393
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 Pop984,487
With Disability119,072
Pct With Disability12.1%

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 · Total19,979

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

Other

Census Mobility · Total984,840
Census Mobility · Same House868,162
Census Mobility · Same County67,049
Census Mobility · Diff County Same State24,515
Census Mobility · Diff State19,562
Census Mobility · From Abroad5,552
Census Mobility · Moved Total116,678
Census Mobility · Pct Moved In Year11.8%
Pct White62.1%

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