County Maps US

Loudoun County, Virginia

A county in Virginia, ranked 4 of 133 by population.

CountyFIPS 51107

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

Download SVGFull Virginia map downloads

Population
449,749
+27,056 (+6.4%) since 2020
Land area
515.7
square miles. A further 1.1% of the total area is water
Population density
872
people per square mile, computed rather than published
County seat
Leesburg
Seat of county government.
Established
1757
268 years ago
Largest city
Leesburg town
Population 49,917.

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 Loudoun 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 Loudoun 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 800 by 779 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 Loudoun 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
Population449,7494th of 133167th of 3,144
Land area515.7 sq mi20th of 1332,023rd of 3,144
Population density872 per sq mi38th of 133178th of 3,144
Median household income$181,7651st of 1331st of 3,143

Full data for Loudoun County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population449,749Vintage 2025 Population Estimates
Population in 2020422,693Vintage 2025 Population Estimates
2020 estimates base?420,951Vintage 2025 Population Estimates
Land area515.7 sq mi2025 Gazetteer Files
Water area5.6 sq mi2025 Gazetteer Files
Total area521.3 sq mi2025 Gazetteer Files
Population density?872 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$181,765American Community Survey 2020-2024 5-Year Estimates
Median home value$743,800American Community Survey 2020-2024 5-Year Estimates
Median age38.2American Community Survey 2020-2024 5-Year Estimates
Households143,032American Community Survey 2020-2024 5-Year Estimates
Housing units147,003American 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
+2,755
4,603 births, 1,848 deaths
Net migration
+3,200
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 8 areas bordering Loudoun 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
Montgomery CountyMaryland21 mi1,074,582
Fairfax CountyVirginia18 mi1,167,873
Fauquier CountyVirginia17 mi76,503
Jefferson CountyWest Virginia16 mi63,102
Frederick CountyMaryland16 mi302,883
Prince William CountyVirginia13 mi502,966
Clarke CountyVirginia12 mi15,609
Washington CountyMaryland2.5 mi157,731

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

Side by side

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.