Decatur County, Indiana
County seat: Greensburg · Population 26,576 (2025) · 373 sq mi
Decatur County is the 59th most populous of Indiana's 92 counties, with 26,576 people (2025 estimate). Its county seat is Greensburg. It is part of the Southeast (Region 9) region, one of the 12 Indiana economic growth regions (DWD / WorkOne regions). The map shows its 5 cities and towns and the 6 neighboring counties.
Decatur County facts
- County seat
- Greensburg
- Population (2025 estimate)
- 26,576 +0.4% since 2020
- Land area
- 373 sq mi 62nd largest of 92
- Water area
- 1 sq mi
- Population density
- 71 per sq mi
- Established
- 1822
- Named after
- Stephen Decatur United States Navy officer
- Largest city
- Greensburg 12,315
- Median household income
- $69,783
- Cities and towns
- 5 plus 9 CDPs
- ZIP codes
- 11
- Time zone
- Eastern
- FIPS code
- 18031
Cities and towns in Decatur County
Decatur County has 5 incorporated cities, towns and villages. Populations count the people living inside Decatur County; cities that cross a county line also list the other counties.
| Name | Type | Population 2025 | Also in |
|---|---|---|---|
| Greensburg (county seat) | City | 12,315 | |
| Westport | Town | 1,406 | |
| St. Paul | Town | 595 | Shelby County |
| New Point | Town | 319 | |
| Millhousen | Town | 145 |
Unincorporated communities (CDPs)
Census-designated places are communities without their own city government; the county provides their services.
| Community | Population | Also in |
|---|---|---|
| Lake Santee | 820 | Franklin County |
| Sandusky | 200 | |
| Letts | 154 | |
| Sardinia | 130 | |
| Adams | 121 | |
| Clarksburg | 76 | |
| Milford | 67 | |
| St. Omer | 19 | |
| Burney | 0 |
ZIP codes in Decatur County
11 ZIP codes reach into Decatur County. ZIP codes ignore county lines, so some also cover a neighboring county.
- 46156 also Rush County
- 46173 also Rush, Franklin and Fayette counties
- 47006 also Ripley and Franklin counties
- 47225
- 47240 also Shelby, Franklin, Ripley and Rush counties
- 47244 also Bartholomew County
- 47246 also Bartholomew County
- 47263
- 47265 also Jennings County
- 47272 also Shelby and Rush counties
- 47283 also Jennings and Bartholomew counties
Population of Decatur County, 2020–2025
Decatur County grew by 106 people (+0.4%) between April 2020 and July 2025: 72 more deaths than births and a net gain of 179 people from migration.
| Year (July 1) | Population |
|---|---|
| 2020 | 26,467 |
| 2021 | 26,308 |
| 2022 | 26,409 |
| 2023 | 26,366 |
| 2024 | 26,514 |
| 2025 | 26,576 |
Neighboring counties
- Rush County north · 16,767 people
- Bartholomew County west · 85,729 people
- Jennings County south · 27,622 people
- Franklin County east · 23,286 people
- Shelby County northwest · 45,882 people
- Ripley County southeast · 29,434 people
Printable Decatur County map
The PDF is a vector file with real text: it prints sharp on Letter paper and you can search it for a town. The PNG is 2400 pixels wide for slides and documents. Both are free to use with a credit to WhichCounty.
- PDF (Letter) (76 KB)
- PNG (2400 px) (64 KB)
Paste this code to embed the map on your site:
Sources
- Boundaries: U.S. Census Bureau, 2025 Cartographic Boundary Files (1:500,000).
- Population: Census Bureau county and city estimates, Vintage 2025. CDP populations: American Community Survey 2020–2024.
- Places and ZIP codes: Census Bureau 2026 Gazetteer and 2020 ZIP Code Tabulation Area relationship files.
- County seat, founding year and name origin: Wikidata (CC0), checked against state sources.
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