51 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Calais | 1 | 3,110 | 3,084 | 0.16% | 91 | 34 | City |
| Calais | 2 | 3,100 | 3,084 | -0.16% | 90 | 34 | City |
| Machias | 3 | 2,044 | 2,063 | -0.78% | 147 | 14 | Town |
| Milbridge | 4 | 1,353 | 1,368 | -1.17% | 56 | 24 | Town |
| East Machias | 5 | 1,327 | 1,318 | -0.45% | 38 | 35 | Town |
| Baileyville | 6 | 1,304 | 1,319 | -0.53% | 35 | 37 | Town |
| Eastport | 7 | 1,294 | 1,283 | 0.15% | 356 | 4 | City |
| Eastport | 8 | 1,288 | 1,283 | -0.31% | 354 | 4 | City |
| Jonesport | 9 | 1,244 | 1,240 | -0.56% | 44 | 29 | Town |
| Lubec | 10 | 1,233 | 1,234 | -0.32% | 37 | 33 | Town |
| Addison | 11 | 1,181 | 1,150 | 0.17% | 28 | 42 | Town |
| Steuben | 12 | 1,169 | 1,133 | 0.78% | 27 | 43 | Town |
| Cherryfield | 13 | 1,087 | 1,105 | -0.73% | 24 | 45 | Town |
| Machiasport | 14 | 1,012 | 973 | 0.1% | 47 | 21 | Town |
| Harrington | 15 | 992 | 965 | 0.61% | 47 | 21 | Town |
| Perry | 16 | 788 | 802 | -0.76% | 27 | 29 | Town |
| Pembroke | 17 | 780 | 787 | -0.38% | 29 | 27 | Town |
| Passamaquoddy Indian Township Reservation | 18 | 759 | 760 | -0.52% | 20 | 38 | Township |
| Princeton | 19 | 750 | 748 | -0.27% | 20 | 37 | Town |
| Passamaquoddy Pleasant Point Reservation | 20 | 690 | 690 | -0.14% | 1,221 | 1 | Township |
| Jonesboro | 21 | 609 | 578 | 0.16% | 17 | 37 | Town |
| Milbridge | 22 | 601 | 532 | 7.13% | 328 | 2 | CDP |
| Danforth | 23 | 592 | 524 | 7.05% | 239 | 2 | CDP |
| Danforth | 24 | 591 | 589 | -0.17% | 11 | 54 | Town |
| Robbinston | 25 | 553 | 542 | 0% | 20 | 28 | Town |
| Marshfield | 26 | 539 | 529 | 0.75% | 32 | 17 | Town |
| Cutler | 27 | 522 | 522 | 0% | 11 | 47 | Town |
| Alexander | 28 | 517 | 523 | -0.58% | 13 | 40 | Town |
| Whiting | 29 | 513 | 487 | 2.4% | 11 | 47 | Town |
| Columbia Falls | 30 | 483 | 474 | -0.21% | 20 | 25 | Town |
| Beals | 31 | 458 | 446 | 0.44% | 82 | 6 | Town |
| Columbia | 32 | 435 | 434 | -0.23% | 12 | 36 | Town |
| Charlotte | 33 | 339 | 337 | 0% | 11 | 31 | Town |
| Roque Bluffs | 34 | 317 | 294 | 1.28% | 31 | 10 | Town |
| Dennysville | 35 | 314 | 302 | 0% | 21 | 15 | Town |
| Lubec | 36 | 284 | 400 | -1.39% | 546 | 1 | CDP |
| Whitneyville | 37 | 205 | 202 | -0.49% | 14 | 15 | Town |
| Baring | 38 | 199 | 201 | -0.5% | 10 | 21 | Plantation |
| Vanceboro | 39 | 193 | 166 | 7.22% | 269 | 1 | CDP |
| Topsfield | 40 | 179 | 180 | -0.56% | 4 | 50 | Town |
| Northfield | 41 | 177 | 178 | -0.56% | 4 | 44 | Town |
| Cooper | 42 | 170 | 172 | -0.58% | 6 | 31 | Town |
| Meddybemps | 43 | 136 | 136 | 0% | 10 | 13 | Town |
| Grand Lake Stream | 44 | 127 | 127 | 0% | 3 | 44 | Plantation |
| Wesley | 45 | 121 | 121 | 0% | 2 | 50 | Town |
| Vanceboro | 46 | 103 | 104 | -0.96% | 5 | 20 | Town |
| Crawford | 47 | 95 | 91 | 0% | 3 | 35 | Town |
| Deblois | 48 | 76 | 75 | 0% | 2 | 36 | Town |
| Talmadge | 49 | 70 | 70 | 0% | 2 | 38 | Town |
| Waite | 50 | 68 | 67 | 0% | 2 | 44 | Town |
| Beddington | 51 | 62 | 62 | 0% | 2 | 35 | Town |
Calais is the largest city in Washington County, with a population of 3,110.
Beddington is the smallest city in Washington County, with a population of 62.
There are 51 cities in Washington County, Maine.