Duncan: Demographics & People
Duncan is home to 22,958 people, in 9,492 households. Population grew 0.4% from 22,872 (2022) to 22,958 (2024). Median age 39.9 years. (1.1y younger than Stephens County; 4.7y older than Oklahoma). Children under 18 are 22% of the population. Population is 74% White (non-Hispanic) and 12% Hispanic or Latino. 65% of households are family-led. County is gaining 1,185 residents per year (2022-2023). County health: 42% adult obesity, 18% smoke.
- 2.4 people per household (vs Oklahoma avg 2.6).
- 35% non-family households (singles, roommates) (vs Oklahoma 39%).
- 76 dependents per 100 working-age (youth + seniors / 18-64) (vs Oklahoma 67).
Population & Trend
Population grew 0.4% from 22,872 (2022) to 22,958 (2024) — close to the U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~23,045 (extrapolated at 0.2%/yr trend). Census Bureau Vintage estimate: 23,162.
| Census data vintage | 2024 |
|---|---|
| Population | 42,848 people |
| Annual growth rate · Population change | 0.4% |
| Annual growth rate · Population (2022) | 22,872 |
| Annual growth rate · Population (2024) | 22,958 |
| Annual growth rate · Population growing | Yes |
| Annual growth rate · Trend category | stable |
| Population | 22,958 people (vs Oklahoma 63,420) |
| Population Estimate | 23,162 |
Sources: Census ACS 5-Year 2023, Table B01003 · Refreshed 2026-04-12
Age Distribution
Median age 39.9y is 1.0 years older than the U.S. median (38.9y). Children under 18 make up 22% — near the U.S. share of ~22%.
| Age Summary · Median age | 39.9 years (vs Oklahoma 35.2y) |
|---|---|
| Age Summary · Children Pct | 22.3% |
| Age Summary · Character | family-oriented |
| Age Summary · Total Pop | 22,958 |
| Age Summary · Under 18 | 5,117 |
| Age Summary · 18 To 34 | 4,870.0× |
| Age Summary · 35 To 64 | 8,174.0× |
| Age Summary · 65 Plus | 4,797 |
| Population under 18 | 5,117 |
| Median age | 39.9 years (vs Oklahoma 35.2y) |
Sources: Census ACS 5-Year 2024 — place-level B01001 query · Census ACS 5-Year 2023 · Refreshed 2026-04-29
Race, Ethnicity & Diversity
Of 22,958 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups).
| White residents | 17,832 |
|---|---|
| Black residents | 582 |
| Asian residents | 110 |
| Hispanic or Latino residents | 2,492 |
| Diversity Index · Simpson Index | 37.7% |
| Diversity Index · Interpretation | less diverse |
| Asian population | 0.6% (vs Oklahoma 3.2%) |
| Black population | 2.1% (vs Oklahoma 5.5%) |
| Hispanic or Latino population | 11.7% (vs Oklahoma 12.3%) |
| White (non-Hispanic) population | 73.9% (vs Oklahoma 57.8%) |
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). 0.5% are foreign-born — below the U.S. average of 13.9%. 4% have naturalized to U.S. citizenship.
| Residents born in this state | 14,369 |
|---|---|
| Residents born in another state | 7,611 |
| Share born in this state | 62.6% |
| Share born in another state | 37.4% |
| Native-born U.S. citizens | 33.2% |
| Foreign-born residents | 0.5% |
| Naturalized citizens | 3.7% |
| Total foreign-born residents | 721 |
| From Europe | 112 |
| From Africa | 87 |
Households & Family Composition
9,492 households. Averaging 2.4 people each — smaller than the U.S. average of 2.5. 65% are family households — near the U.S. share of ~65%. Of 6,118 families, 26% are married couples with children.
| Children under 18 | 5,128 |
|---|---|
| Total families | 6,118 |
| Married couples with children | 1,598 |
| Single-parent households | 243 |
| Average household size | 2.40 |
| Women who gave birth (past year) | 13.9% |
| Grandparents living with grandchildren | 335 |
| Grandparents responsible for grandchildren | 111 |
| Family households | 6,184 households (vs Oklahoma 16,590) |
| Households that are families | 65.1% (vs Oklahoma 61.1%) |
| Total households | 9,492 households (vs Oklahoma 23,671) |
Sources: Census ACS 5-Year 2023 · Refreshed 2026-04-12
Residential Stability & Migration
How long residents have lived here and where they came from. 17.3% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 1,185 residents per year on net (IRS migration data).
| Moved within the county (past year) | 17.3% |
|---|---|
| Migration · People moving in (annual) | 38,012 |
| Migration · People moving out (annual) | 36,827 |
| Migration · Net migration (in − out) | 1,185 |
| 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 | 2,275 |
|---|---|
| Disability rate | 10.2% |
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. 479 residents live in group quarters (2.1% of population).
| Living in group quarters | 479 |
|---|
Other
| Congressional District · District | 4 |
|---|---|
| Congressional District · Congress | 118th |
| Cdc Birth Rate · Fips | 40137 |
| Cdc Birth Rate · State Fips | 40 |
| Cdc Birth Rate · County Fips | 137 |
| Cdc Birth Rate · County | Stephens |
| Cdc Birth Rate · Birth Rate | 34.9% |
| Cdc Birth Rate · Lower Ci | 30.30 |
| Cdc Birth Rate · Upper Ci | 40.00 |
| Cdc Mortality · Fips | 40137 |
| Cdc Mortality · County | Stephens County |
| Cdc Mortality · Urban Rural | Micropolitan |
| Cdc Mortality · Total Deaths 2020 2023 | 2,053 |
| Cdc Vaccination · Fips | 40137 |
| Cdc Vaccination · County | Stephens County |
| Cdc Vaccination · Dose1 Pop Pct | 59.7% |
| Cdc Vaccination · Series Complete Pct | 49.7% |
| Cdc Vaccination · Booster Pct | 43.9% |
| Cdc Vaccination · Population 2019 | 43,143 |
| Cdc Vaccination · Metro Status | Non-metro |
| Family Score · Score | 9.20 |
| Family Score · Schools | 11 |
| Family Score · Childcare Centers | 9 |
| Family Score · Children Pct | 22.3% |
| Family Score · Rating | excellent |
| Town Summary · Key Facts | population 22,958, stable, family-oriented, middle-class, mixed |
| Town Summary · Population | 22,958 people (vs Oklahoma 63,420) |
| Town Summary · County | Stephens County |
Sources: NCES school congressional district assignment · federal dataset cascade