29 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% | 2,602 | 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 |
| Oak Grove | 8 | 17,762 | 17,781 | 0.43% | 4,551 | 4 | CDP |
| Damascus | 9 | 13,194 | 10,973 | 7.15% | 749 | 18 | CDP |
| Sandy | 10 | 13,072 | 12,661 | 0.63% | 3,601 | 4 | City |
| Oatfield | 11 | 12,988 | 13,588 | -0.22% | 3,826 | 3 | CDP |
| Gladstone | 12 | 11,861 | 12,046 | -0.31% | 4,946 | 2 | City |
| Molalla | 13 | 10,109 | 10,232 | -0.25% | 4,076 | 2 | City |
| Bull Mountain | 14 | 9,366 | 9,732 | 0.17% | 4,721 | 2 | CDP |
| Jennings Lodge | 15 | 7,749 | 8,500 | 0.38% | 4,874 | 2 | CDP |
| Estacada | 16 | 5,854 | 4,538 | 4.7% | 2,279 | 3 | City |
| Mount Hood Villages | 17 | 5,829 | 4,511 | 7.15% | 260 | 22 | CDP |
| Beavercreek | 18 | 4,544 | 4,105 | 0.09% | 226 | 20 | CDP |
| Boring | 19 | 2,484 | 1,977 | 7.16% | 577 | 4 | CDP |
| Mulino | 20 | 2,228 | 2,178 | 0.36% | 162 | 14 | CDP |
| Dunthorpe | 21 | 2,209 | 1,690 | 7.13% | 2,100 | 1 | CDP |
| Stafford | 22 | 1,565 | 1,940 | 0% | 250 | 6 | CDP |
| Orient | 23 | 635 | 774 | 7.08% | 671 | 1 | CDP |
| Johnson City | 24 | 555 | 543 | 0.36% | 8,538 | 0 | City |
| Rivergrove | 25 | 536 | 545 | -0.37% | 3,098 | 0 | City |
| Butteville | 26 | 290 | 317 | 0.69% | 276 | 1 | CDP |
| Rhododendron | 27 | 184 | 299 | 6.98% | 47 | 4 | CDP |
| Barlow | 28 | 142 | 134 | 0.71% | 2,731 | 0 | City |
| Government Camp | 29 | 78 | 96 | -9.3% | 104 | 1 | CDP |
Lake Oswego is the largest city in Clackamas County, with a population of 39,814.
Government Camp is the smallest city in Clackamas County, with a population of 78.
There are 29 cities in Clackamas County, Oregon.