| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Omak | 1 | 5,254 | 4,861 | 1.33% | 1,395 | 4 | City |
| Okanogan | 2 | 2,518 | 2,374 | 0.96% | 1,252 | 2 | City |
| Brewster | 3 | 2,114 | 1,986 | 1% | 1,835 | 1 | City |
| Oroville | 4 | 1,957 | 1,814 | 1.14% | 1,158 | 2 | City |
| Coulee Dam | 5 | 1,245 | 1,213 | 0.32% | 1,739 | 1 | Town |
| Twisp | 6 | 1,152 | 999 | 2.31% | 985 | 1 | Town |
| Tonasket | 7 | 1,139 | 1,100 | 0.53% | 1,207 | 1 | City |
| Pateros | 8 | 660 | 600 | 0.92% | 1,307 | 1 | City |
| Winthrop | 9 | 647 | 507 | 3.69% | 672 | 1 | Town |
| Riverside | 10 | 346 | 327 | 0.87% | 390 | 1 | Town |
| Elmer City | 11 | 260 | 244 | 0.78% | 1,092 | 0 | Town |
| Nespelem | 12 | 200 | 187 | 1.01% | 1,031 | 0 | Town |
| Conconully | 13 | 199 | 191 | 0.51% | 943 | 0 | Town |
Omak is the largest city in Okanogan County, with a population of 5,254.
Conconully is the smallest city in Okanogan County, with a population of 199.
There are 13 cities in Okanogan County, Washington.