19 ZIP Codes
| Zip Code | City | Population ↓ |
|---|---|---|
| 04841 | Rockland | 7,035 |
| 04843 | Camden | 5,242 |
| 04864 | Warren | 4,932 |
| 04862 | Union | 4,023 |
| 04856 | Rockport | 3,675 |
| 04861 | Thomaston | 2,769 |
| 04847 | Hope | 1,748 |
| 04574 | Washington | 1,624 |
| 04860 | Tenants Harbor | 1,543 |
| 04854 | Owls Head | 1,482 |
| 04563 | Cushing | 1,460 |
| 04858 | South Thomaston | 1,378 |
| 04863 | Vinalhaven | 1,216 |
| 04547 | Friendship | 1,213 |
| 04859 | Spruce Head | 753 |
| 04853 | North Haven | 480 |
| 04855 | Port Clyde | 313 |
| 04645 | Isle Au Haut | 69 |
| 04851 | Matinicus | 48 |
The data shown reflect ZCTAs from the US Census. As of 2025, there are 19 ZCTAs in Knox County, Maine (US Census).