Founded in 1839, DeWitt County is one of 102 counties in the state of Illinois. Historically, DeWitt County was formed from Macon and McLean County. The city of Clinton is the county seat. With FIPS code of 39, DeWitt County has a population of 15,341 and area of 397 square miles (1,028 km2).
List of all cities in DeWitt County, IL alphabetically
| City/Town | Postal Code | Area Code |
| Barnett Township, IL | 61727 | 217 |
| Birkbeck, IL | 61727 | 217 |
| Clinton, IL | 61727 | 217 |
| Clintonia Township, IL | 61727 | 217 |
| Dewitt, IL | 61735 | 217 |
| Farmer City, IL | 61842 | 309 |
| Hallsville, IL | 61727 | 217 |
| Harp Township, IL | 61727 | 217 |
| Jenkins, IL | 61727 | 217 |
| Kenney, IL | 61749 | 217 |
| Lane, IL | 61750 | 217 |
| Midland City, IL | 61727 | 217 |
| Ospur, IL | 61727 | 217 |
| South Clinton, IL | 61727 | 217 |
| Tabor, IL | 61778 | 217 |
| Texas Township, IL | 61727 | 217 |
| Tunbridge, IL | 61749 | 217 |
| Wapella, IL | 61777 | 217 |
| Waynesville, IL | 61778 | 217 |
| Weldon, IL | 61882 | 217 |