St. Elmo: Demographics & People
St. Elmo is home to 1,257 people, in 456 households. Population shrank 10.3% from 1,401 (2022) to 1,257 (2024). Median age 40.1 years. (1.8y younger than Fayette County; 1.0y older than Illinois). Children under 18 are 24% of the population. Population is 94% White (non-Hispanic) and 1% Hispanic or Latino. The community is relatively homogeneous (Simpson index 0.03). 54% of households are family-led. County is losing 437 residents per year (2022-2023). County health: 37% adult obesity, 16% smoke.
- 2.8 people per household.
- 46% non-family households (singles, roommates).
Population & Trend
Population shrank 10.3% from 1,401 (2022) to 1,257 (2024). Estimated 2026 population: ~1,131 (extrapolated at -5.1%/yr trend). Census Bureau Vintage estimate: 975.
| Census data vintage | 2024 |
|---|---|
| Population | 21,488 people |
| Annual growth rate · Population change | -10.3% |
| Annual growth rate · Population (2022) | 1,401 |
| Annual growth rate · Population (2024) | 1,257 |
| Annual growth rate · Trend category | shrinking |
| Population | 1,257 people |
| Population Estimate | 975 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 40.1y is 1.2 years older than the U.S. median (38.9y). Children under 18 make up 24% — above the U.S. share of ~22%.
| Age Summary · Median age | 40.1 years (vs Illinois 39.1y) |
|---|---|
| Age Summary · Children Pct | 23.7% |
| Age Summary · Character | established |
| Population under 18 | 298 |
| Median age | 40.1 years (vs Illinois 39.1y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 1,257 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.03 (0 = single group, 1 = perfectly even distribution); this is read as relatively homogeneous.
| White residents | 1,358 |
|---|---|
| Black residents | 9 |
| Hispanic or Latino residents | 14 |
| Diversity Index · Diversity index (Simpson) | 3.3% |
| Diversity Index · Diversity label | relatively homogeneous |
| Diversity Index · Groups counted | 3 |
| Diversity Index · Largest group share | 98.3% |
| Black population | 0.8% |
| Hispanic or Latino population | 1.0% |
| White (non-Hispanic) population | 94.5% |
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 | 1,109 |
|---|---|
| Residents born in another state | 137 |
| Share born in this state | 88.2% |
| Share born in another state | 11.8% |
| Native-born U.S. citizens | 10.9% |
| Naturalized citizens | 0.9% |
| Total foreign-born residents | 10 |
| From Europe | 10 |
Households & Family Composition
456 households. Averaging 2.7 people each — larger than the U.S. average of 2.5. 54% are family households — below the U.S. share of ~65%. Of 282 families, 30% are married couples with children.
| Children under 18 | 329 |
|---|---|
| Total families | 282 |
| Married couples with children | 85 |
| Single-parent households | 3 |
| Average household size | 2.74 |
| Women who gave birth (past year) | 20.1% |
| Grandparents living with grandchildren | 25 |
| Grandparents responsible for grandchildren | 2 |
| Family households | 248 households |
| Households that are families | 54.4% |
| Total households | 456 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. 7.9% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is losing 437 residents per year on net (IRS migration data).
| Moved within the county (past year) | 7.9% |
|---|---|
| Migration · People moving in (annual) | 17,932 |
| Migration · People moving out (annual) | 18,369 |
| Migration · Net migration (in − out) | -437 |
| 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 | 132 |
|---|---|
| Disability rate | 9.7% |
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. 50 residents live in group quarters (4.0% of population).
| Living in group quarters | 50 |
|---|
Other
| Congressional District · District | 15 |
|---|---|
| Congressional District · Formatted | IL-15 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 17,051 |
| Cdc Birth Rate · State Fips | 17 |
| Cdc Birth Rate · County Fips | 51 |
| Cdc Birth Rate · County | Fayette |
| Cdc Birth Rate · Birth Rate | 33.5% |
| Cdc Birth Rate · Lower Ci | 27.20 |
| Cdc Birth Rate · Upper Ci | 40.80 |
| Cdc Mortality · Fips | 17,051 |
| Cdc Mortality · County | Fayette County |
| Cdc Mortality · Urban Rural | Noncore |
| Cdc Mortality · Total Deaths 2020 2023 | 676 |
| Cdc Vaccination · Fips | 17,051 |
| Cdc Vaccination · County | Fayette County |
| Cdc Vaccination · Dose1 Pop Pct | 40.2% |
| Cdc Vaccination · Series Complete Pct | 37.0% |
| Cdc Vaccination · Booster Pct | 52.8% |
| Cdc Vaccination · Population 2019 | 21,336 |
| Cdc Vaccination · Metro Status | Non-metro |
| Family Score · Score | 7.00 |
| Family Score · Schools | 12 |
| Family Score · Children Pct | 23.7% |
| Family Score · Rating | good |
| Town Summary · Key Facts | population 1,257, shrinking, established, working-class, blue collar |
| Town Summary · Population | 1,257 people |
| Town Summary · County | Fayette County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade