County Maps US

Johnston County, North Carolina

A county in North Carolina, ranked 9 of 100 by population.

CountyFIPS 37101

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

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Population
256,448
+38,998 (+17.9%) since 2020
Land area
792
square miles. A further 0.5% of the total area is water
Population density
324
people per square mile, computed rather than published
County seat
Smithfield
Seat of county government.
Established
1746
279 years ago
Largest city
Clayton town
Population 32,633 for the whole place, which extends beyond this county.

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 Johnston 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 Johnston 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 750 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 Johnston 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
Population256,4489th of 100288th of 3,144
Land area792 sq mi10th of 1001,085th of 3,144
Population density324 per sq mi19th of 100410th of 3,144
Median household income$83,38411th of 100472nd of 3,143

Full data for Johnston County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population256,448Vintage 2025 Population Estimates
Population in 2020217,450Vintage 2025 Population Estimates
2020 estimates base?216,014Vintage 2025 Population Estimates
Land area792 sq mi2025 Gazetteer Files
Water area3.6 sq mi2025 Gazetteer Files
Total area795.7 sq mi2025 Gazetteer Files
Population density?324 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$83,384American Community Survey 2020-2024 5-Year Estimates
Median home value$305,600American Community Survey 2020-2024 5-Year Estimates
Median age38.1American Community Survey 2020-2024 5-Year Estimates
Households85,591American Community Survey 2020-2024 5-Year Estimates
Housing units91,218American 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
+936
2,879 births, 1,943 deaths
Net migration
+6,026
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 7 areas bordering Johnston 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
Wake CountyNorth Carolina33 mi1,257,235
Wayne CountyNorth Carolina32 mi122,278
Harnett CountyNorth Carolina21 mi150,137
Sampson CountyNorth Carolina15 mi61,504
Wilson CountyNorth Carolina15 mi81,150
Nash CountyNorth Carolina11 mi99,365
Franklin CountyNorth Carolinaa single point82,037

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.