| Zip Code | City | Population ↓ |
|---|---|---|
| 52057 | Manchester | 8,082 |
| 52040 | Dyersville | 5,644 |
| 52041 | Earlville | 1,901 |
| 52237 | Hopkinton | 1,623 |
| 52223 | Delhi | 1,162 |
| 52330 | Ryan | 943 |
| 52038 | Dundee | 529 |
| 52050 | Greeley | 433 |
| 52036 | Delaware | 139 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 9 ZCTAs in Delaware County, Iowa (US Census).