County Maps US

Posey County, Indiana

A county in Indiana, ranked 63 of 92 by population.

CountyFIPS 18129

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

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Population
24,988
-202 (-0.8%) since 2020
Land area
409.4
square miles. A further 2.4% of the total area is water
Population density
61.0
people per square mile, computed rather than published
County seat
Mount Vernon
Seat of county government.
Established
1814
211 years ago
Largest city
Mount Vernon city
Population 6,289.

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 Posey 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 Posey County, Indiana 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 589 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 Posey County ranks

Position among the 92 counties of Indiana, and among all 3,144 US counties and county-equivalents. Computed from the figures on this page.

MeasureValueIn IndianaNationally
Population24,98863rd of 921,623rd of 3,144
Land area409.4 sq mi35th of 922,467th of 3,144
Population density61.0 per sq mi63rd of 921,292nd of 3,144
Median household income$78,12916th of 92664th of 3,143

Full data for Posey County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population24,988Vintage 2025 Population Estimates
Population in 202025,190Vintage 2025 Population Estimates
2020 estimates base?25,227Vintage 2025 Population Estimates
Land area409.4 sq mi2025 Gazetteer Files
Water area10.2 sq mi2025 Gazetteer Files
Total area419.6 sq mi2025 Gazetteer Files
Population density?61.0 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$78,129American Community Survey 2020-2024 5-Year Estimates
Median home value$222,900American Community Survey 2020-2024 5-Year Estimates
Median age43.0American Community Survey 2020-2024 5-Year Estimates
Households10,533American Community Survey 2020-2024 5-Year Estimates
Housing units11,105American 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
-41
208 births, 249 deaths
Net migration
-30
More people moved out than moved in.

Source: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026. Retrieved 30 August 2026.

The 6 areas bordering Posey 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
White CountyIllinois54 mi13,250
Gibson CountyIndiana20 mi33,091
Vanderburgh CountyIndiana19 mi181,995
Union CountyKentucky16 mi12,839
Henderson CountyKentucky16 mi44,255
Gallatin CountyIllinois15 mi4,616

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

All 92 counties of Indiana

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

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