| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Astoria | 1 | 9,774 | 10,189 | -0.65% | 1,600 | 6 | City |
| Seaside | 2 | 7,081 | 7,173 | -0.16% | 1,749 | 4 | City |
| Warrenton | 3 | 6,331 | 6,289 | 0.3% | 500 | 13 | City |
| Gearhart | 4 | 1,877 | 1,804 | 0.86% | 1,004 | 2 | City |
| Cannon Beach | 5 | 1,512 | 1,514 | 0% | 967 | 2 | City |
Astoria is the largest city in Clatsop County, with a population of 9,774.
Cannon Beach is the smallest city in Clatsop County, with a population of 1,512.
There are 5 cities in Clatsop County, Oregon.