8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Nampa | 1 | 121,330 | 101,430 | 3.39% | 3,489 | 35 | City |
| Caldwell | 2 | 76,174 | 60,743 | 4.22% | 3,239 | 24 | City |
| Middleton | 3 | 12,270 | 9,567 | 4.6% | 2,007 | 6 | City |
| Parma | 4 | 2,222 | 2,101 | 1.09% | 2,056 | 1 | City |
| Wilder | 5 | 1,757 | 1,596 | 1.86% | 2,410 | 1 | City |
| Greenleaf | 6 | 787 | 811 | -0.63% | 1,022 | 1 | City |
| Melba | 7 | 638 | 570 | 2.08% | 1,396 | 0 | City |
| Notus | 8 | 604 | 611 | -0.33% | 1,624 | 0 | City |
Nampa is the largest city in Canyon County, with a population of 121,330.
Notus is the smallest city in Canyon County, with a population of 604.
There are 8 cities in Canyon County, Idaho.