| Zip Code | City | Population ↓ |
|---|---|---|
| 4901 | Waterville | 26,463 |
| 4330 | Augusta | 26,394 |
| 4345 | Gardiner | 12,282 |
| 4963 | Oakland | 7,376 |
| 4364 | Winthrop | 6,138 |
| 4989 | Vassalboro | 4,526 |
| 4358 | South China | 4,434 |
| 4350 | Litchfield | 3,605 |
| 4259 | Monmouth | 3,410 |
| 4927 | Clinton | 3,381 |
| 4917 | Belgrade | 3,258 |
| 4344 | Farmingdale | 2,988 |
| 4363 | Windsor | 2,643 |
| 4355 | Readfield | 2,616 |
| 4347 | Hallowell | 2,558 |
| 4351 | Manchester | 2,387 |
| 4910 | Albion | 2,311 |
| 4352 | Mount Vernon | 1,618 |
| 4346 | Randolph | 1,522 |
| 4349 | Kents Hill | 1,302 |
| 4284 | Wayne | 1,069 |
| 4265 | North Monmouth | 697 |
| 4360 | Vienna | 642 |
| 4359 | South Gardiner | 326 |
| 4918 | Belgrade Lakes | 0 |
| 4926 | China Village | 0 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 26 ZCTAs in Kennebec County, Maine (US Census).