St. John: Demographics & People
St. John is home to 22,567 people, in 7,844 households. Population grew 4.3% from 21,639 (2022) to 22,567 (2024). Median age 42.3 years. (2.6y older than Lake County; 4.1y older than Indiana). Children under 18 are 24% of the population. Population is 79% White (non-Hispanic) and 14% Hispanic or Latino. The community is somewhat diverse (Simpson index 0.28). 81% of households are family-led. County is gaining 812 residents per year (2022-2023). County health: 38% adult obesity, 17% smoke.
- 2.9 people per household.
- 19% non-family households (singles, roommates).
Population & Trend
Population grew 4.3% from 21,639 (2022) to 22,567 (2024) — about 7.2× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~23,545 (extrapolated at 2.1%/yr trend). Census Bureau Vintage estimate: 24,891.
| Census data vintage | 2024 |
|---|---|
| Population | 498,700 people |
| Annual growth rate · Population change | 4.3% |
| Annual growth rate · Population (2022) | 21,639 |
| Annual growth rate · Population (2024) | 22,567 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | growing |
| Population | 22,567 people |
| Population Estimate | 24,891 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 42.3y is 3.4 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 | 42.3 years (vs Indiana 38.2y) |
|---|---|
| Age Summary · Children Pct | 24.2% |
| Age Summary · Character | established |
| Population under 18 | 5,451 |
| Median age | 42.3 years (vs Indiana 38.2y) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Race, Ethnicity & Diversity
Of 22,567 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.28 (0 = single group, 1 = perfectly even distribution); this is read as somewhat diverse.
| White residents | 18,267 |
|---|---|
| Black residents | 598 |
| Asian residents | 525 |
| Hispanic or Latino residents | 2,299 |
| Diversity Index · Diversity index (Simpson) | 27.8% |
| Diversity Index · Diversity label | somewhat diverse |
| Diversity Index · Groups counted | 4 |
| Diversity Index · Largest group share | 84.2% |
| Asian population | 2.0% |
| Black population | 2.3% |
| Hispanic or Latino population | 13.6% |
| White (non-Hispanic) population | 78.7% |
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). 0.6% are foreign-born — below the U.S. average of 13.9%. 6% have naturalized to U.S. citizenship.
| Residents born in this state | 10,180 |
|---|---|
| Residents born in another state | 10,999 |
| Share born in this state | 45.1% |
| Share born in another state | 54.9% |
| Native-born U.S. citizens | 48.7% |
| Foreign-born residents | 0.6% |
| Naturalized citizens | 5.5% |
| Total foreign-born residents | 1,169 |
| From Europe | 506 |
| From Africa | 316 |
Households & Family Composition
7,844 households. Averaging 2.9 people each — larger than the U.S. average of 2.5. 81% are family households — above the U.S. share of ~65%. Of 6,140 families, 35% are married couples with children.
| Children under 18 | 5,388 |
|---|---|
| Total families | 6,140 |
| Married couples with children | 2,143 |
| Single-parent households | 103 |
| Average household size | 2.87 |
| Women who gave birth (past year) | 6.4% |
| Grandparents living with grandchildren | 396 |
| Grandparents responsible for grandchildren | 99 |
| Family households | 6,385 households |
| Households that are families | 81.4% |
| Total households | 7,844 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. 5.1% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 812 residents per year on net (IRS migration data).
| Moved within the county (past year) | 5.1% |
|---|---|
| Migration · People moving in (annual) | 438,163 |
| Migration · People moving out (annual) | 437,351 |
| Migration · Net migration (in − out) | 812 |
| Migration · Population growing | Yes |
| 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 | 1,488 |
|---|---|
| Disability rate | 7.2% |
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. 70 residents live in group quarters (0.3% of population).
| Living in group quarters | 70 |
|---|
Other
| Congressional District · District | 1 |
|---|---|
| Congressional District · Formatted | IN-01 |
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 18,089 |
| Cdc Birth Rate · State Fips | 18 |
| Cdc Birth Rate · County Fips | 89 |
| Cdc Birth Rate · County | Lake |
| Cdc Birth Rate · Birth Rate | 20.2% |
| Cdc Birth Rate · Lower Ci | 19.10 |
| Cdc Birth Rate · Upper Ci | 21.50 |
| Cdc Mortality · Fips | 18,089 |
| Cdc Mortality · County | Lake County |
| Cdc Mortality · Urban Rural | Large fringe metro |
| Cdc Mortality · Total Deaths 2020 2023 | 23,079 |
| Cdc Vaccination · Fips | 18,089 |
| Cdc Vaccination · County | Lake County |
| Cdc Vaccination · Dose1 Pop Pct | 67.3% |
| Cdc Vaccination · Series Complete Pct | 60.0% |
| Cdc Vaccination · Booster Pct | 49.1% |
| Cdc Vaccination · Population 2019 | 485,493 |
| Cdc Vaccination · Metro Status | Metro |
| Family Score · Score | 10 |
| Family Score · Schools | 20 |
| Family Score · Childcare Centers | 1 |
| Family Score · Children Pct | 24.2% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 22,567, growing, established, affluent, white collar |
| Town Summary · Population | 22,567 people |
| Town Summary · County | Lake County |
Sources: Census place-to-CD118 crosswalk (place_fips) · federal dataset cascade