19 zips
| Zip Code | City | Population ↓ |
|---|---|---|
| 04841 | Rockland | 6,991 |
| 04843 | Camden | 5,243 |
| 04864 | Warren | 4,893 |
| 04862 | Union | 4,195 |
| 04856 | Rockport | 3,663 |
| 04861 | Thomaston | 2,761 |
| 04847 | Hope | 1,711 |
| 04574 | Washington | 1,618 |
| 04860 | Tenants Harbor | 1,506 |
| 04563 | Cushing | 1,407 |
| 04858 | South Thomaston | 1,400 |
| 04854 | Owls Head | 1,375 |
| 04547 | Friendship | 1,276 |
| 04863 | Vinalhaven | 1,063 |
| 04859 | Spruce Head | 810 |
| 04853 | North Haven | 488 |
| 04855 | Port Clyde | 316 |
| 04851 | Matinicus | 85 |
| 04645 | Isle Au Haut | 59 |
The data shown reflect ZCTAs from the US Census. As of 2024, there are 19 ZCTAs in Knox County, Maine (US Census).