Zip Code | City | Population |
|---|---|---|
| 19901 | Dover | 39,097 |
| 19904 | Dover | 37,387 |
| 19977 | Smyrna | 26,204 |
| 19934 | Camden Wyoming | 14,566 |
| 19943 | Felton | 12,600 |
| 19962 | Magnolia | 12,277 |
| 19952 | Harrington | 10,602 |
| 19938 | Clayton | 9,240 |
| 19946 | Frederica | 5,497 |
| 19953 | Hartly | 4,972 |
| 19954 | Houston | 1,688 |
| 19964 | Marydel | 1,599 |
| 19979 | Viola | 541 |
| 19955 | Kenton | 384 |
| 19936 | Cheswold | 222 |
| 19980 | Woodside | 152 |
| 19902 | Dover Afb | 64 |