| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Belfast | 1 | 6,976 | 6,954 | -0.17% | 205 | 34 | City |
| Winterport | 2 | 3,822 | 3,829 | -0.42% | 108 | 36 | Town |
| Searsport | 3 | 2,777 | 2,646 | 1.46% | 97 | 29 | Town |
| Lincolnville | 4 | 2,449 | 2,319 | 0.66% | 66 | 37 | Town |
| Unity | 5 | 2,291 | 2,289 | -0.69% | 58 | 39 | Town |
| Northport | 6 | 1,653 | 1,551 | 0.79% | 70 | 24 | Town |
| Palermo | 7 | 1,639 | 1,571 | 0.18% | 40 | 41 | Town |
| Stockton Springs | 8 | 1,591 | 1,543 | -0.13% | 81 | 20 | Town |
| Searsmont | 9 | 1,502 | 1,410 | 1.21% | 40 | 38 | Town |
| Swanville | 10 | 1,449 | 1,373 | 0.98% | 73 | 20 | Town |
| Frankfort | 11 | 1,244 | 1,232 | -0.32% | 51 | 25 | Town |
| Troy | 12 | 1,125 | 1,023 | 0.81% | 32 | 35 | Town |
| Burnham | 13 | 1,103 | 1,099 | -0.45% | 28 | 39 | Town |
| Morrill | 14 | 1,041 | 975 | 0.97% | 63 | 17 | Town |
| Belmont | 15 | 1,028 | 975 | 0.69% | 76 | 14 | Town |
| Brooks | 16 | 1,021 | 1,009 | -0.2% | 41 | 25 | Town |
| Montville | 17 | 1,020 | 1,019 | -0.49% | 24 | 43 | Town |
| Liberty | 18 | 940 | 940 | -0.53% | 36 | 26 | Town |
| Monroe | 19 | 936 | 933 | -0.53% | 24 | 39 | Town |
| Waldo | 20 | 893 | 796 | 2.29% | 46 | 19 | Town |
| Knox | 21 | 809 | 809 | -0.25% | 28 | 29 | Town |
| Thorndike | 22 | 801 | 777 | -0.12% | 32 | 25 | Town |
| Freedom | 23 | 756 | 713 | 1.48% | 35 | 22 | Town |
| Prospect | 24 | 702 | 690 | -0.14% | 39 | 18 | Town |
| Jackson | 25 | 611 | 610 | -0.49% | 24 | 25 | Town |
| Islesboro | 26 | 596 | 581 | 0% | 42 | 14 | Town |
Belfast is the largest city in Waldo County, with a population of 6,976.
Islesboro is the smallest city in Waldo County, with a population of 596.
There are 26 cities in Waldo County, Maine.