13 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Calais | 1 | 3,128 | 3,083 | 0.03% | 91 | 34.32 | City |
| Machias | 2 | 2,094 | 2,059 | 0.43% | 151 | 13.89 | Town |
| Milbridge | 3 | 1,379 | 1,363 | -0.29% | 57 | 24.25 | Town |
| East Machias | 4 | 1,347 | 1,318 | 0.15% | 39 | 34.93 | Town |
| Baileyville | 5 | 1,313 | 1,317 | -0.3% | 35 | 37.25 | Town |
| Eastport | 6 | 1,296 | 1,284 | -0.15% | 357 | 3.63 | City |
| Jonesport | 7 | 1,270 | 1,240 | 0.24% | 45 | 28.51 | Town |
| Lubec | 8 | 1,243 | 1,232 | -0.08% | 37 | 33.24 | Town |
| Addison | 9 | 1,213 | 1,148 | 1.25% | 29 | 42.45 | Town |
| Steuben | 10 | 1,152 | 1,132 | 0% | 27 | 43.01 | Town |
| Cherryfield | 11 | 1,102 | 1,107 | -0.27% | 25 | 44.53 | Town |
| Machiasport | 12 | 1,004 | 0 | -0.2% | 47 | 21.40 | Town |
| Harrington | 13 | 1,003 | 0 | 0% | 48 | 21.11 | Town |
Calais is the largest city in Washington County, with a population of 3,128.
Harrington is the smallest city in Washington County.
There are 13 cities in Washington County, Maine.