St. Ann: Demographics & People
St. Ann's population stands at 12,811 people, in 5,880 households. Population shrank 0.4% from 12,865 (2022) to 12,811 (2024). Median age 34.8 years. (5.5y younger than St. Louis County; 4.4y younger than Missouri). Children under 18 are 24% of the population. Population is 55% White (non-Hispanic) and 24% Black. The community is moderately diverse (Simpson index 0.53). 53% of households are family-led. County is losing 10,393 residents per year (2022-2023). County health: 33% adult obesity, 17% smoke.
- 2.2 people per household.
- 47% non-family households (singles, roommates).
Population & Trend
Population shrank 0.4% from 12,865 (2022) to 12,811 (2024). Estimated 2026 population: ~12,757 (extrapolated at -0.2%/yr trend). Census Bureau Vintage estimate: 12,685.
| Census data vintage | 2024 |
|---|---|
| Population | 1,004,125 people |
| Annual growth rate · Population change | -0.4% |
| Annual growth rate · Population (2022) | 12,865 |
| Annual growth rate · Population (2024) | 12,811 |
| Annual growth rate · Trend category | stable |
| Population | 12,811 people |
| Population Estimate | 12,685 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 34.8y is 4.1 years younger than the U.S. median (38.9y). Children under 18 make up 24% — above the U.S. share of ~22%.
| Age Summary · Median age | 34.8 years (vs Missouri 39.2y) |
|---|---|
| Age Summary · Children Pct | 23.6% |
| Age Summary · Character | young professional |
| Population under 18 | 3,022 |
| Median age | 34.8 years (vs Missouri 39.2y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 12,811 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.53 (0 = single group, 1 = perfectly even distribution); this is read as moderately diverse.
| White residents | 8,089 |
|---|---|
| Black residents | 3,402 |
| Asian residents | 217 |
| Hispanic or Latino residents | 1,235 |
| Diversity Index · Diversity index (Simpson) | 53.1% |
| Diversity Index · Diversity label | moderately diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 62.5% |
| Asian population | 2.1% |
| Black population | 24.5% |
| Hispanic or Latino population | 12.9% |
| White (non-Hispanic) population | 55.1% |
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). 0.9% are foreign-born — below the U.S. average of 13.9%. 11% have naturalized to U.S. citizenship.
| Residents born in this state | 8,951 |
|---|---|
| Residents born in another state | 2,318 |
| Share born in this state | 69.9% |
| Share born in another state | 30.1% |
| Native-born U.S. citizens | 18.1% |
| Foreign-born residents | 0.9% |
| Naturalized citizens | 11.2% |
| Total foreign-born residents | 633 |
| From Europe | 75 |
| From Africa | 103 |
Households & Family Composition
5,880 households. Averaging 2.1 people each — smaller than the U.S. average of 2.5. 53% are family households — below the U.S. share of ~65%. Of 3,123 families, 19% are married couples with children.
| Children under 18 | 2,633 |
|---|---|
| Total families | 3,123 |
| Married couples with children | 597 |
| Single-parent households | 240 |
| Average household size | 2.08 |
| Women who gave birth (past year) | 14.8% |
| Grandparents living with grandchildren | 267 |
| Grandparents responsible for grandchildren | 70 |
| Family households | 3,123 households |
| Households that are families | 53.1% |
| Total households | 5,880 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. 11.5% 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) | 11.5% |
|---|---|
| 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 | 1,192 |
|---|---|
| Disability rate | 9.2% |
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. 20 residents live in group quarters (0.2% of population).
| Living in group quarters | 20 |
|---|
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 | 23.6% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 12,811, stable, young professional, middle-class, mixed |
| Town Summary · Population | 12,811 people |
| Town Summary · County | St. Louis County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade