County Maps US

Marion County, Oregon

A county in Oregon, ranked 5 of 36 by population.

CountyFIPS 41047

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

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Population
355,777
+9,493 (+2.7%) since 2020
Land area
1,181
square miles. A further 0.9% of the total area is water
Population density
301
people per square mile, computed rather than published
County seat
Salem
Seat of county government.
Established
1843
182 years ago
Largest city
Salem city
Population 151,399 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 Marion 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 Marion 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 505 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 Marion 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
Population355,7775th of 36214th of 3,144
Land area1,181 sq mi25th of 36519th of 3,144
Population density301 per sq mi3rd of 36437th of 3,144
Median household income$77,35111th of 36707th of 3,143

Full data for Marion County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population355,777Vintage 2025 Population Estimates
Population in 2020346,284Vintage 2025 Population Estimates
2020 estimates base?345,926Vintage 2025 Population Estimates
Land area1,181 sq mi2025 Gazetteer Files
Water area10.2 sq mi2025 Gazetteer Files
Total area1,191 sq mi2025 Gazetteer Files
Population density?301 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$77,351American Community Survey 2020-2024 5-Year Estimates
Median home value$416,400American Community Survey 2020-2024 5-Year Estimates
Median age37.5American Community Survey 2020-2024 5-Year Estimates
Households126,870American Community Survey 2020-2024 5-Year Estimates
Housing units132,295American 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
+605
3,844 births, 3,239 deaths
Net migration
+1,929
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 Marion 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
Clackamas CountyOregon95 mi426,280
Linn CountyOregon88 mi132,843
Polk CountyOregon34 mi90,037
Yamhill CountyOregon30 mi110,024
Jefferson CountyOregon19 mi25,740
Wasco CountyOregon4.7 mi26,310

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

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.