Founded on Dec 12, 1821, Decatur County is one of 92 counties in the state of Indiana. Historically, Decatur County was formed from Delaware New Purchase. The city of Greensburg is the county seat. With FIPS code of 31, Decatur County has a population of 26,320 and area of 373 square miles (966 km2).
List of all cities in Decatur County, IN alphabetically
| City/Town | Postal Code | Area Code |
| Adams, IN | 47240 | 812 |
| Alert, IN | 47283 | 812 |
| Burney, IN | 47240 | 812 |
| Clarksburg, IN | 47225 | 812 |
| Enochsburg, IN | 47240 | 812 |
| Greensburg, IN | 47240 | 812 |
| Kingston, IN | 47240 | 812 |
| Lake McCoy, IN | 47240 | 812 |
| Millhousen, IN | 47261 | 812 |
| New Point, IN | 47263 | 812 |
| Quailtown, IN | 47283 | 812 |
| Saint Paul, IN | 47272 | 317 |
| Sandusky, IN | 47240 | 812 |
| Sardinia, IN | 47283 | 812 |
| Westport, IN | 47283 | 812 |
| Williamstown, IN | 47240 | 812 |