County outline
Where Jennings County is located
Area breakdown
Land accounts for 99.5% of Jennings County’s measured area and water for 0.5%. Its combined area converts to 979.9 square kilometers or approximately 242,141 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 376.601 | 975.392 | 241,024.6 |
| Water | 1.745 | 4.52 | 1,116.8 |
| Total | 378.346 | 979.912 | 242,141.4 |
How Jennings County compares
By original Census land area, Jennings County ranks #60 of 92 in Indiana and #2615 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.95 times the Indiana county-equivalent median of 396.4 square miles. It accounts for 1.1% of the combined county land area in the state.
See the complete Indiana ranking · What counts as a county equivalent?
Population and density of Jennings County
The Census Bureau estimates that 27,622 people lived in Jennings County on July 1, 2025. That ranks #1,566 of 3,222 county equivalents nationally and #58 of 92 in Indiana. Since the April 1, 2020 estimates base of 27,617, the population has grown by 5 (+0%), compared with +2.8% for Indiana as a whole.
With 376.6 square miles of land, that is 73 people per square mile (28 per km²), placing Jennings County #1,224 nationally for density and #56 in Indiana. The median county equivalent has 47 people per square mile; the Indiana median is 88. Put another way, there are about 8.7 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 27,587 | 27,510 | 27,467 | 27,630 | 27,724 | 27,622 |
| Change | — | −77 | −43 | +163 | +94 | −102 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Jennings County
2 incorporated places lie at least partly in Jennings County. Together they are home to 6,791 people (24.6%); the other 20,831 (75.4%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is North Vernon city, with 6,559 residents in the county. The county seat, Vernon town, has 232 residents.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| North Vernon city | 6,559 | −0.9% | 7.877 |
| Vernon townCounty seat | 232 | −0.9% | 0.207 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Jennings County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Jennings County is not part of any metropolitan or micropolitan statistical area in the Office of Management and Budget’s July 2023 delineation; 1,306 other county equivalents are also outside one. These areas are built around an urban core of at least 10,000 people plus the counties tied to it by commuting, so counties outside them are generally rural.
ZIP codes
13 ZIP Code Tabulation Areas have land in Jennings County; 6 of them have most of their land inside the county, and the others mainly cover neighboring areas.
47037472234722747229472304723147232472654727047273472744728247283
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Jennings County
Jennings County shares a land border with 6 county equivalents. It has more land than 3 of them. The largest neighbor is Jackson County (510 mi²) and the smallest is Scott County (190.4 mi²). Together with its neighbors, Jennings County forms a block of 2,663.6 mi² of land, of which it holds 14.1%.
| Bordering county equivalent | Land mi² | Size vs. Jennings | Compare |
|---|---|---|---|
| Jackson County | 510 | 1.4× larger | Compare |
| Ripley County | 446.4 | 1.2× larger | Compare |
| Bartholomew County | 406.9 | 1.1× larger | Compare |
| Decatur County | 372.6 | about the same | Compare |
| Jefferson County | 360.7 | about the same | Compare |
| Scott County | 190.4 | 2× smaller | Compare |
How big is Jennings County compared with U.S. states?
Jennings County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.7 times as much. Indiana’s county land could hold about 95 areas the size of Jennings County.
Another way to picture it: the same land area would fill a square about 19.4 miles (31.2 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Jennings County?
Jennings County has more land than 607 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Jennings County at #2,663 nationally by total area, 48 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 0.5%, compared with a national county-equivalent median of 1.2% — 0.7 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Jennings County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2614 | White County, Tennessee | 376.7 | Compare |
| #2615 | Jennings County, Indiana | 376.6 | This county |
| #2616 | Houston County, Georgia | 376.2 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 38.996314, -85.628075. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 975,392,027 m²; AWATER: 4,518,579 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Jennings County?
Jennings County, Indiana has 376.6 square miles (975.4 km²) of land and 1.745 square miles of water, for a total area of 378.3 square miles. It ranks #2615 of 3,222 U.S. county equivalents by land area.
Is Jennings County the largest county in Indiana?
No. Jennings County ranks #60 of 92 in Indiana by land area. The largest is Allen County, with 657.1 square miles of land.
What counties border Jennings County?
Jennings County shares a land border with Ripley County, Jackson County, Jefferson County, Decatur County, Bartholomew County, and Scott County.
What is the population of Jennings County?
The Census Bureau estimates Jennings County had 27,622 residents on July 1, 2025, ranking #1,566 of 3,222 county equivalents. That is 73 people per square mile of land.
What is the county seat of Jennings County?
The county seat of Jennings County is Vernon.
What cities and towns are in Jennings County?
Jennings County has 2 incorporated places. The most populous are North Vernon city and Vernon town; 20,831 residents live outside any incorporated place.
Is Jennings County part of a metropolitan area?
No. Jennings County is outside every metropolitan and micropolitan statistical area in the July 2023 OMB delineation.
How many ZIP codes are in Jennings County?
13 ZIP Code Tabulation Areas have land in Jennings County, and 6 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Jennings County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.7 times as much land.
How many acres of land are in Jennings County?
The land measurement converts to approximately 241,025 acres. Including water, total area is approximately 242,141 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.