| Zip Code | City | Population ↓ |
|---|---|---|
| 06239 | Danielson | 11,185 |
| 06260 | Putnam | 9,266 |
| 06234 | Brooklyn | 8,517 |
| 06374 | Plainfield | 7,838 |
| 06281 | Woodstock | 7,237 |
| 06241 | Dayville | 6,585 |
| 06354 | Moosup | 6,031 |
| 06331 | Canterbury | 5,145 |
| 06259 | Pomfret Center | 4,568 |
| 06255 | North Grosvenordale | 4,494 |
| 06278 | Ashford | 4,337 |
| 06277 | Thompson | 4,004 |
| 06377 | Sterling | 2,927 |
| 06384 | Voluntown | 2,663 |
| 06247 | Hampton | 2,412 |
| 06235 | Chaplin | 2,018 |
| 06242 | Eastford | 1,290 |
| 06282 | Woodstock Valley | 1,134 |
| 06332 | Central Village | 1,015 |
| 06262 | Quinebaug | 813 |
| 06263 | Rogers | 498 |
| 06373 | Oneco | 219 |
| 06387 | Wauregan | 178 |
| 06264 | Scotland | 139 |
| 06258 | Pomfret | 114 |
| 06243 | East Killingly | 83 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 26 ZCTAs in Northeastern Connecticut Planning Region, Connecticut (US Census).