County Maps US

Osage County, Missouri

A county in Missouri, ranked 73 of 115 by population.

CountyFIPS 29151

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

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Population
13,611
+361 (+2.7%) since 2020
Land area
606.6
square miles. A further 1.1% of the total area is water
Population density
22.4
people per square mile, computed rather than published
County seat
Linn
Seat of county government.
Established
1841
184 years ago
Largest city
Linn city
Population 1,453.

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 Osage 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 Osage County, Missouri 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 775 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 Osage County ranks

Position among the 115 counties of Missouri, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn MissouriNationally
Population13,61173rd of 1152,183rd of 3,144
Land area606.6 sq mi53rd of 1151,603rd of 3,144
Population density22.4 per sq mi72nd of 1152,148th of 3,144
Median household income$76,68111th of 115740th of 3,143

Full data for Osage County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population13,611Vintage 2025 Population Estimates
Population in 202013,250Vintage 2025 Population Estimates
2020 estimates base?13,264Vintage 2025 Population Estimates
Land area606.6 sq mi2025 Gazetteer Files
Water area6.8 sq mi2025 Gazetteer Files
Total area613.4 sq mi2025 Gazetteer Files
Population density?22.4 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$76,681American Community Survey 2020-2024 5-Year Estimates
Median home value$223,300American Community Survey 2020-2024 5-Year Estimates
Median age41.1American Community Survey 2020-2024 5-Year Estimates
Households5,287American Community Survey 2020-2024 5-Year Estimates
Housing units6,501American 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
+27
170 births, 143 deaths
Net migration
+116
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 Osage 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
Cole CountyMissouri30 mi77,908
Maries CountyMissouri30 mi8,397
Gasconade CountyMissouri29 mi14,784
Callaway CountyMissouri23 mi45,765
Miller CountyMissouri3.0 mi25,817
Montgomery CountyMissouri0.4 mi11,590

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

All 115 counties of Missouri

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

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