St. John: Demographics & People
St. John's population stands at 6,527 people, in 2,741 households. Population shrank 0.5% from 6,562 (2022) to 6,527 (2024). Median age 36.0 years. (4.3y younger than St. Louis County; 3.2y younger than Missouri). Children under 18 are 22% of the population. Population is 48% White (non-Hispanic) and 36% Black. The community is highly diverse (Simpson index 0.64). 61% of households are family-led. County is losing 10,393 residents per year (2022-2023). County health: 33% adult obesity, 17% smoke.
- 2.4 people per household.
- 39% non-family households (singles, roommates).
Population & Trend
Population shrank 0.5% from 6,562 (2022) to 6,527 (2024). Estimated 2026 population: ~6,492 (extrapolated at -0.3%/yr trend). Census Bureau Vintage estimate: 6,446.
| Census data vintage | 2024 |
|---|---|
| Population | 1,004,125 people |
| Annual growth rate · Population change | -0.5% |
| Annual growth rate · Population (2022) | 6,562 |
| Annual growth rate · Population (2024) | 6,527 |
| Annual growth rate · Trend category | stable |
| Population | 6,527 people |
| Population Estimate | 6,446 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 36.0y is 2.9 years younger than the U.S. median (38.9y). Children under 18 make up 22% — near the U.S. share of ~22%.
| Age Summary · Median age | 36.0 years (vs Missouri 39.2y) |
|---|---|
| Age Summary · Children Pct | 22.1% |
| Age Summary · Character | family-oriented |
| Population under 18 | 1,444 |
| Median age | 36.0 years (vs Missouri 39.2y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 6,527 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.64 (0 = single group, 1 = perfectly even distribution); this is read as highly diverse.
| White residents | 2,715 |
|---|---|
| Black residents | 2,474 |
| Asian residents | 145 |
| Hispanic or Latino residents | 971 |
| Diversity Index · Diversity index (Simpson) | 63.6% |
| Diversity Index · Diversity label | highly diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 43.1% |
| Asian population | 0.4% |
| Black population | 36.2% |
| Hispanic or Latino population | 12.1% |
| White (non-Hispanic) population | 48.1% |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Ancestry
Self-reported ancestry from Census ACS — what residents report as their ethnic origin, separate from race. Counts can exceed population because people can list multiple ancestries.
Top (8)
Citizenship & Origin
Where residents were born and their citizenship status (Census ACS).
| Residents born in this state | 4,946 |
|---|---|
| Residents born in another state | 1,060 |
| Share born in this state | 75.8% |
| Share born in another state | 24.2% |
| Native-born U.S. citizens | 16.2% |
| Naturalized citizens | 8.0% |
| Total foreign-born residents | 392 |
| From Europe | 21 |
| From Africa | 153 |
Households & Family Composition
2,741 households. Averaging 2.3 people each — smaller than the U.S. average of 2.5. 61% are family households — below the U.S. share of ~65%. Of 1,800 families, 26% are married couples with children.
| Children under 18 | 1,413 |
|---|---|
| Total families | 1,800 |
| Married couples with children | 463 |
| Single-parent households | 71 |
| Average household size | 2.30 |
| Women who gave birth (past year) | 18.3% |
| Grandparents living with grandchildren | 101 |
| Family households | 1,678 households |
| Households that are families | 61.2% |
| Total households | 2,741 households |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Residential Stability & Migration
How long residents have lived here and where they came from. 8.3% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 10,393 residents per year on net (IRS migration data).
| Moved within the county (past year) | 8.3% |
|---|---|
| Migration · People moving in (annual) | 897,558 |
| Migration · People moving out (annual) | 907,951 |
| Migration · Net migration (in − out) | -10,393 |
| Migration · Year | 2022-2023 |
Sources: IRS SOI Migration 2021-2022 · Refreshed 2026-04-12
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.
| Residents with a disability | 487 |
|---|---|
| Disability rate | 7.5% |
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. 63 residents live in group quarters (1.0% of population).
| Living in group quarters | 63 |
|---|
Other
| Congressional District · District | 1 |
|---|---|
| Congressional District · Formatted | MO-01 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 29,189 |
| Cdc Birth Rate · State Fips | 29 |
| Cdc Birth Rate · County Fips | 189 |
| Cdc Birth Rate · County | St Louis |
| Cdc Birth Rate · Birth Rate | 13.0% |
| Cdc Birth Rate · Lower Ci | 12.30 |
| Cdc Birth Rate · Upper Ci | 13.70 |
| Cdc Mortality · Fips | 29,189 |
| Cdc Mortality · County | St. Louis County |
| Cdc Mortality · Urban Rural | Large fringe metro |
| Cdc Mortality · Total Deaths 2020 2023 | 48,207 |
| Cdc Vaccination · Fips | 29,189 |
| Cdc Vaccination · County | St. Louis County |
| Cdc Vaccination · Dose1 Pop Pct | 79.7% |
| Cdc Vaccination · Series Complete Pct | 68.5% |
| Cdc Vaccination · Booster Pct | 55.1% |
| Cdc Vaccination · Population 2019 | 994,205 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 10 |
| Family Score · Schools | 20 |
| Family Score · Children Pct | 22.1% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 6,527, stable, family-oriented, middle-class, mixed |
| Town Summary · Population | 6,527 people |
| Town Summary · County | St. Louis County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade