11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Astoria | 1 | 9,847 | 10,194 | -0.7% | 1,612 | 6.11 | City |
| Seaside | 2 | 7,156 | 7,175 | -0.06% | 1,767 | 4.05 | City |
| Warrenton | 3 | 6,233 | 6,288 | -0.18% | 492 | 12.66 | City |
| Gearhart | 4 | 1,909 | 1,811 | 1.06% | 1,021 | 1.87 | City |
| Cannon Beach | 5 | 1,504 | 1,501 | 0.07% | 962 | 1.56 | City |
| Knappa | 6 | 1,181 | 1,033 | 7.17% | 572 | 2.07 | CDP |
| Svensen | 7 | 1,015 | 877 | 7.18% | 453 | 2.24 | CDP |
| Westport | 8 | 378 | 329 | 0.8% | 570 | 0.66 | CDP |
| River Point | 9 | 292 | 242 | 6.96% | 560 | 0.52 | CDP |
| Barnesdale | 10 | 231 | 188 | 6.94% | 310 | 0.74 | CDP |
| Jeffers Gardens | 11 | 146 | 312 | 7.35% | 258 | 0.56 | CDP |
Astoria is the largest city in Clatsop County, with a population of 9,847.
Jeffers Gardens is the smallest city in Clatsop County.
There are 11 cities in Clatsop County, Oregon.