County Maps US

Onslow County, North Carolina

A county in North Carolina, ranked 13 of 100 by population.

CountyFIPS 37133

Within North Carolina
Onslow County, highlighted, with the areas around it. Boundaries generalised from the 2025 Census cartographic boundary file; neighbour fills carry no data. The dot marks Jacksonville, the county seat, located via the 2025 Census Gazetteer.

Download SVGFull North Carolina map downloads

Population
217,175
+12,191 (+5.9%) since 2020
Land area
762.1
square miles. A further 15.8% of the total area is water
Population density
285
people per square mile, computed rather than published
County seat
Jacksonville
Seat of county government.
Established
1734
291 years ago
Largest city
Jacksonville city
Population 72,732.

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; Wikidata (CC0), Wikidata. Retrieved 30 August 2026.

Satellite view

Aerial imagery of Onslow County with its boundary drawn on top. A map shows you the shape; this shows you what is inside it, and which side of the line a place falls on.

Aerial view of Onslow County, North Carolina from the USGS National Map, with its boundary outlined
Imagery: USGS National Map, USGS Imagery Only, public domain, requested from USGS by your browser when you reach this point on the page, at 707 by 800 pixels. The boundary is the 2025 Census cartographic boundary file, reprojected to Web Mercator to match the imagery. You can also open the USGS National Map viewer.

Where Onslow County ranks

Position among the 100 counties of North Carolina, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn North CarolinaNationally
Population217,17513th of 100331st of 3,144
Land area762.1 sq mi12th of 1001,145th of 3,144
Population density285 per sq mi21st of 100458th of 3,144
Median household income$68,14826th of 1001,328th of 3,143

Full data for Onslow County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population217,175Vintage 2025 Population Estimates
Population in 2020204,984Vintage 2025 Population Estimates
2020 estimates base?204,475Vintage 2025 Population Estimates
Land area762.1 sq mi2025 Gazetteer Files
Water area143.1 sq mi2025 Gazetteer Files
Total area905.2 sq mi2025 Gazetteer Files
Population density?285 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$68,148American Community Survey 2020-2024 5-Year Estimates
Median home value$236,400American Community Survey 2020-2024 5-Year Estimates
Median age27.7American Community Survey 2020-2024 5-Year Estimates
Households75,265American Community Survey 2020-2024 5-Year Estimates
Housing units87,354American Community Survey 2020-2024 5-Year Estimates

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Population density is computed here, not published: it divides the Vintage 2025 population estimate by the 2025 Gazetteer land area, which are two different Census products. Retrieved 30 August 2026.

How the population changed

The Census Bureau publishes the components behind an estimate, not just the total. For the year to July 2025:

Births minus deaths
+2,141
3,718 births, 1,577 deaths
Net migration
+357
More people moved in than moved out.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 4 areas bordering Onslow County

Ordered by the length of the border actually shared, which the Census Bureau publishes in its county adjacency file and which no other county reference presents.

Bordering areaStateShared borderPopulation
Jones CountyNorth Carolina49 mi9,575
Pender CountyNorth Carolina27 mi72,111
Carteret CountyNorth Carolina20 mi70,469
Duplin CountyNorth Carolina18 mi51,571

Source: US Census Bureau, County Adjacency File, 2025 County Adjacency File, released 15 September 2025. Retrieved 30 August 2026.

All 100 counties of North Carolina

Open the interactive North Carolina county map, or jump straight to any of them.

Data on this page last rebuilt 30 August 2026. How these figures are produced.