10 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Puget Island | 1 | 1,113 | 1,227 | 1.64% | 147 | 8 | CDP |
| East Cathlamet | 2 | 652 | 512 | 1.56% | 381 | 2 | CDP |
| Cathlamet | 3 | 619 | 561 | 1.81% | 1,223 | 1 | Town |
| Cathlamet | 4 | 619 | 563 | 1.81% | 1,223 | 1 | Town |
| Lower Elochoman | 5 | 510 | 475 | 4.51% | 338 | 2 | CDP |
| Rosburg | 6 | 457 | 320 | 2.01% | 20 | 23 | CDP |
| Skamokawa Valley | 7 | 260 | 268 | -3.35% | 9 | 28 | CDP |
| Grays River | 8 | 256 | 309 | 0% | 13 | 20 | CDP |
| Upper Elochoman | 9 | 85 | 119 | -8.6% | 59 | 1 | CDP |
| Altoona | 10 | 66 | 35 | 6.45% | 13 | 5 | CDP |
Puget Island is the largest city in Wahkiakum County, with a population of 1,113.
Altoona is the smallest city in Wahkiakum County, with a population of 66.
There are 10 cities in Wahkiakum County, Washington.