| Locality | Post Code |
|---|---|
| Barnett, DeWitt | 61727 |
| Birkbeck, DeWitt | 61727 |
| Clinton, DeWitt | 61727 |
| Clintonia, DeWitt | 61727 |
| De Witt, DeWitt | 61735 |
| Farmer City, DeWitt | 61842 |
| Hallsville, DeWitt | 61727 |
| Harp, DeWitt | 61727 |
| Jenkins, DeWitt | 61727 |
| Kenney, DeWitt | 61749 |
| Lane, DeWitt | 61750 |
| Midland City, DeWitt | 61727 |
| Ospur, DeWitt | 61727 |
| South Clinton, DeWitt | 61727 |
| Tabor, DeWitt | 61778 |
| Texas, DeWitt | 61727 |
| Tunbridge, DeWitt | 61749 |
| Wapella, DeWitt | 61777 |
| Waynesville, DeWitt | 61778 |
| Weldon, DeWitt | 61882 |