County Maps US

Washington County, Oregon

A county in Oregon, ranked 2 of 36 by population.

CountyFIPS 41067

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

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Population
611,708
+10,704 (+1.8%) since 2020
Land area
724.3
square miles. A further 0.3% of the total area is water
Population density
845
people per square mile, computed rather than published
County seat
Hillsboro
Seat of county government.
Established
1843
182 years ago
Largest city
Hillsboro city
Population 111,126.

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 Washington 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 Washington County, Oregon 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 722 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 Washington County ranks

Position among the 36 counties of Oregon, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn OregonNationally
Population611,7082nd of 36114th of 3,144
Land area724.3 sq mi31st of 361,227th of 3,144
Population density845 per sq mi2nd of 36186th of 3,144
Median household income$107,7721st of 36111th of 3,143

Full data for Washington County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population611,708Vintage 2025 Population Estimates
Population in 2020601,004Vintage 2025 Population Estimates
2020 estimates base?600,368Vintage 2025 Population Estimates
Land area724.3 sq mi2025 Gazetteer Files
Water area2.4 sq mi2025 Gazetteer Files
Total area726.6 sq mi2025 Gazetteer Files
Population density?845 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$107,772American Community Survey 2020-2024 5-Year Estimates
Median home value$588,000American Community Survey 2020-2024 5-Year Estimates
Median age38.1American Community Survey 2020-2024 5-Year Estimates
Households235,406American Community Survey 2020-2024 5-Year Estimates
Housing units243,278American 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
+1,776
5,878 births, 4,102 deaths
Net migration
+1,285
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 Washington 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
Tillamook CountyOregon49 mi27,384
Yamhill CountyOregon37 mi110,024
Multnomah CountyOregon29 mi795,391
Columbia CountyOregon25 mi54,091
Clackamas CountyOregon16 mi426,280
Clatsop CountyOregona single point40,926

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

Side by side

All 36 counties of Oregon

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

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