6 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Port Townsend | 1 | 10,721 | 10,173 | 1.04% | 1,544 | 6.94 | City |
| Port Hadlock-Irondale | 2 | 3,263 | 3,329 | -0.64% | 488 | 6.69 | CDP |
| Port Ludlow | 3 | 3,219 | 2,940 | 1.29% | 279 | 11.53 | CDP |
| Brinnon | 4 | 893 | 889 | 0.68% | 93 | 9.59 | CDP |
| Marrowstone | 5 | 891 | 943 | 0.34% | 141 | 6.30 | CDP |
| Quilcene | 6 | 613 | 664 | 0.16% | 70 | 8.81 | CDP |
Port Townsend is the largest city in Jefferson County, with a population of 10,721.
Quilcene is the smallest city in Jefferson County.
There are 6 cities in Jefferson County, Washington.