County Maps US

Jay County, Indiana

A county in Indiana, ranked 71 of 92 by population.

CountyFIPS 18075

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

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Population
20,118
-362 (-1.8%) since 2020
Land area
383.9
square miles. A further 0.0% of the total area is water
Population density
52.4
people per square mile, computed rather than published
County seat
Portland
Seat of county government.
Established
1836
189 years ago
Largest city
Portland city
Population 6,237.

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 Jay 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 Jay 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 800 by 683 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 Jay 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
Population20,11871st of 921,818th of 3,144
Land area383.9 sq mi56th of 922,590th of 3,144
Population density52.4 per sq mi74th of 921,422nd of 3,144
Median household income$54,96988th of 922,475th of 3,143

Full data for Jay County

Every figure below is attributed to the Census Bureau product it came from, with the vintage of that product.
MeasureValueSource and vintage
Population20,118Vintage 2025 Population Estimates
Population in 202020,480Vintage 2025 Population Estimates
2020 estimates base?20,479Vintage 2025 Population Estimates
Land area383.9 sq mi2025 Gazetteer Files
Water area0.18 sq mi2025 Gazetteer Files
Total area384.1 sq mi2025 Gazetteer Files
Population density?52.4 per sq miComputed: Vintage 2025 estimates divided by 2025 Gazetteer land area
Median household income$54,969American Community Survey 2020-2024 5-Year Estimates
Median home value$117,500American Community Survey 2020-2024 5-Year Estimates
Median age39.5American Community Survey 2020-2024 5-Year Estimates
Households7,807American Community Survey 2020-2024 5-Year Estimates
Housing units8,904American 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
+29
292 births, 263 deaths
Net migration
-169
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 7 areas bordering Jay 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
Randolph CountyIndiana22 mi24,438
Mercer CountyOhio15 mi42,737
Adams CountyIndiana14 mi36,650
Blackford CountyIndiana14 mi11,730
Wells CountyIndiana7.0 mi28,883
Delaware CountyIndiana5.0 mi113,106
Darke CountyOhio2.9 mi51,520

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.