Founded in 1873, Decatur County is one of 105 counties in the state of Kansas. Historically, Decatur County was formed from unorganized area. The city of Oberlin is the county seat. With FIPS code of 39, Decatur County has a population of 2,751 and area of 894 square miles (2,315 km2).
List of all cities in Decatur County, KS alphabetically
| City/Town | Postal Code | Area Code |
| Dresden, KS | 67635 | 785 |
| Jennings, KS | 67643 | 785 |
| Norcatur, KS | 67653 | 785 |
| Oberlin, KS | 67749 | 785 |