14 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Lake Oswego | 1 | 39,814 | 40,889 | -0.54% | 3,676 | 11 | City |
| Oregon City | 2 | 38,465 | 37,774 | 0.36% | 3,828 | 10 | City |
| Happy Valley | 3 | 30,186 | 24,098 | 4.2% | 2,536 | 12 | City |
| Wilsonville | 4 | 28,188 | 26,723 | 1.05% | 3,733 | 8 | City |
| West Linn | 5 | 26,403 | 27,373 | -0.73% | 3,554 | 7 | City |
| Milwaukie | 6 | 21,732 | 21,172 | 0.52% | 4,360 | 5 | City |
| Canby | 7 | 17,979 | 18,219 | -0.27% | 3,827 | 5 | City |
| Sandy | 8 | 13,072 | 12,661 | 0.63% | 3,601 | 4 | City |
| Gladstone | 9 | 11,861 | 12,046 | -0.31% | 4,946 | 2 | City |
| Molalla | 10 | 10,109 | 10,232 | -0.25% | 4,076 | 2 | City |
| Estacada | 11 | 5,854 | 4,538 | 4.7% | 2,279 | 3 | City |
| Johnson City | 12 | 555 | 543 | 0.36% | 8,538 | 0 | City |
| Rivergrove | 13 | 536 | 545 | -0.37% | 3,098 | 0 | City |
| Barlow | 14 | 142 | 134 | 0.71% | 2,731 | 0 | City |
Lake Oswego is the largest city in Clackamas County, with a population of 39,814.
Barlow is the smallest city in Clackamas County, with a population of 142.
There are 14 cities in Clackamas County, Oregon.