County Maps US

Northumberland County, Virginia

A county in Virginia, ranked 107 of 133 by population.

CountyFIPS 51133

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

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Population
12,557
+719 (+6.1%) since 2020
Land area
191.4
square miles. A further 33.0% of the total area is water
Population density
65.6
people per square mile, computed rather than published
County seat
Heathsville
Seat of county government.
Established
1648
377 years ago
Largest city
Kilmarnock town
Population 76 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 Northumberland 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 Northumberland County, Virginia 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 740 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 Northumberland County ranks

Position among the 133 counties and independent cities of Virginia, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn VirginiaNationally
Population12,557107th of 1332,249th of 3,144
Land area191.4 sq mi88th of 1333,012th of 3,144
Population density65.6 per sq mi88th of 1331,233rd of 3,144
Median household income$66,48070th of 1331,468th of 3,143

Full data for Northumberland County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population12,557Vintage 2025 Population Estimates
Population in 202011,838Vintage 2025 Population Estimates
2020 estimates base?11,835Vintage 2025 Population Estimates
Land area191.4 sq mi2025 Gazetteer Files
Water area94.2 sq mi2025 Gazetteer Files
Total area285.6 sq mi2025 Gazetteer Files
Population density?65.6 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$66,480American Community Survey 2020-2024 5-Year Estimates
Median home value$346,800American Community Survey 2020-2024 5-Year Estimates
Median age59.5American Community Survey 2020-2024 5-Year Estimates
Households5,640American Community Survey 2020-2024 5-Year Estimates
Housing units9,044American 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
-110
88 births, 198 deaths
Net migration
+260
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 6 areas bordering Northumberland 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
Lancaster CountyVirginia29 mi10,995
St. Mary's CountyMaryland19 mi116,692
Accomack CountyVirginia15 mi33,859
Richmond CountyVirginia14 mi9,294
Westmoreland CountyVirginia10 mi19,715
Somerset CountyMaryland0.1 mi24,973

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

All 133 counties and independent cities of Virginia

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

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