9 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Yreka | 1 | 7,626 | 7,805 | -0.39% | 764 | 10 | City |
| Mount Shasta | 2 | 3,076 | 3,220 | -0.77% | 816 | 4 | City |
| Weed | 3 | 2,520 | 2,859 | -2.17% | 523 | 5 | City |
| Dunsmuir | 4 | 1,575 | 1,703 | -1.32% | 982 | 2 | City |
| Montague | 5 | 1,145 | 1,220 | -1.04% | 644 | 2 | City |
| Tulelake | 6 | 835 | 900 | -1.3% | 2,037 | 0 | City |
| Dorris | 7 | 797 | 856 | -1.24% | 1,135 | 1 | City |
| Fort Jones | 8 | 653 | 701 | -1.21% | 1,085 | 1 | City |
| Etna | 9 | 627 | 674 | -1.26% | 819 | 1 | City |
Yreka is the largest city in Siskiyou County, with a population of 7,626.
Etna is the smallest city in Siskiyou County, with a population of 627.
There are 9 cities in Siskiyou County, California.