Millsboro: Demographics & People

About 7,424 people live in Millsboro, in 3,276 households. Population grew 3.8% from 7,152 (2022) to 7,424 (2024). Median age 39.5 years. (12.4y younger than Sussex County; 2.5y older than Delaware). Children under 18 are 20% of the population. Population is 62% White (non-Hispanic) and 17% Black. The community is moderately diverse (Simpson index 0.47). 58% of households are family-led. County is gaining 17,165 residents per year (2022-2023). County health: 39% adult obesity, 16% smoke.

Population & Trend

Population grew 3.8% from 7,152 (2022) to 7,424 (2024) — about 6.3× the recent U.S. annual rate of ~0.6%/yr. Estimated 2026 population: ~7,708 (extrapolated at 1.9%/yr trend). Census Bureau Vintage estimate: 8,098.

Census data vintage2024
Population237,378 people
Annual growth rate · Population change3.8%
Annual growth rate · Population (2022)7,152
Annual growth rate · Population (2024)7,424
Annual growth rate · Population growingYes
Annual growth rate · Trend categorygrowing
Population7,424 people (vs Delaware 13,439) population: 4 observations from 2026-04-17 to 2026-04-28
Population Estimate8,098

Sources: Census ACS 5-Year 2023, Table B01003  ·  Refreshed 2026-04-12

Age Distribution

Median age 39.5y is 0.6 years older than the U.S. median (38.9y). Children under 18 make up 20% — below the U.S. share of ~22%.

Age Summary · Median age39.5 years (vs Delaware 37.0y)
Age Summary · Children Pct20.1%
Age Summary · Characterfamily-oriented
Age Summary · Total Pop7,424
Age Summary · Under 181,491
Age Summary · 18 To 341,525.0×
Age Summary · 35 To 642,558.0×
Age Summary · 65 Plus1,850
Population under 181,491
Median age39.5 years (vs Delaware 37.0y)

Sources: Census ACS 5-Year 2024 — place-level B01001 query · Census ACS 5-Year 2023  ·  Refreshed 2026-04-29

Race, Ethnicity & Diversity

Of 7,424 residents, race / ethnicity breaks down by Census ACS counts (a person can identify with one or more groups). The Simpson diversity index is 0.47 (0 = single group, 1 = perfectly even distribution); this is read as moderately diverse.

White residents4,637
Black residents1,212
Asian residents87
Hispanic or Latino residents713
Diversity Index · Diversity index (Simpson)46.9%
Diversity Index · Diversity labelmoderately diverse
Diversity Index · Groups counted4
Diversity Index · Largest group share69.7%
Asian population3.6% (vs Delaware 2.9%)
Black population16.8% (vs Delaware 26.7%)
Hispanic or Latino population10.4% (vs Delaware 10.7%)
White (non-Hispanic) population62.3% (vs Delaware 51.8%)

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)

(unnamed)
Black
(unnamed)
Irish
(unnamed)
English
(unnamed)
German
(unnamed)
Hispanic Total
(unnamed)
Italian
(unnamed)
Puerto Rican
(unnamed)
Asian

Citizenship & Origin

Where residents were born and their citizenship status (Census ACS).

Residents born in this state2,933
Residents born in another state3,521
Share born in this state39.5%
Share born in another state60.5%
Total foreign-born residents469
From Europe94
From Africa151
From Latin America18

Households & Family Composition

3,276 households. Averaging 2.4 people each — smaller than the U.S. average of 2.5. 58% are family households — below the U.S. share of ~65%. Of 1,920 families, 25% are married couples with children.

Children under 181,769
Total families1,920
Married couples with children484
Single-parent households75
Average household size2.37
Women who gave birth (past year)15.5%
Grandparents living with grandchildren122
Grandparents responsible for grandchildren45
Family households1,910 households (vs Delaware 3,428)
Households that are families58.3% (at Delaware median)
Total households3,276 households (vs Delaware 5,560) total_households: 2 observations from 2026-04-23 to 2026-04-23

Sources: Census ACS 5-Year 2023  ·  Refreshed 2026-04-12

Residential Stability & Migration

How long residents have lived here and where they came from. 14.5% moved within the county in the past year — the U.S. baseline is roughly 8–10%. The surrounding county is gaining 17,165 residents per year on net (IRS migration data).

Moved within the county (past year)14.5%
Migration · People moving in (annual)246,573
Migration · People moving out (annual)229,408
Migration · Net migration (in − out)17,165
Migration · Population growingYes
Migration · Year2022-2023

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 disability332
Disability rate5.0%

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. 201 residents live in group quarters (2.7% of population).

Living in group quarters201

Other

Congressional District · Congress118th
Cdc Birth Rate · Fips10005
Cdc Birth Rate · State Fips10
Cdc Birth Rate · County Fips005
Cdc Birth Rate · CountySussex
Cdc Birth Rate · Birth Rate27.6%
Cdc Birth Rate · Lower Ci25.40
Cdc Birth Rate · Upper Ci30.00
Cdc Mortality · Fips10005
Cdc Mortality · CountySussex County
Cdc Mortality · Urban RuralMedium metro
Cdc Mortality · Total Deaths 2020 20239,999
Cdc Vaccination · Fips10005
Cdc Vaccination · CountySussex County
Cdc Vaccination · Dose1 Pop Pct86.5%
Cdc Vaccination · Series Complete Pct72.9%
Cdc Vaccination · Booster Pct55.3%
Cdc Vaccination · Population 2019234,225
Cdc Vaccination · Metro StatusMetro
Family Score · Score4.20
Family Score · Schools3
Family Score · Childcare Centers4
Family Score · Youth Sports Orgs1
Family Score · Children Pct20.1%
Family Score · Ratingfair
Town Summary · Key Factspopulation 7,424, growing, family-oriented, upper-middle, white collar
Town Summary · Population7,424 people (vs Delaware 13,439)
Town Summary · CountySussex County

Sources: NCES school congressional district assignment · federal dataset cascade