| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Yreka | 1 | 7,693 | 7,810 | -0.27% | 771 | 10 | City |
| Mount Shasta | 2 | 3,046 | 3,218 | -0.81% | 808 | 4 | City |
| Weed | 3 | 2,542 | 2,859 | -2.34% | 528 | 5 | City |
| Dunsmuir | 4 | 1,565 | 1,701 | -1.39% | 976 | 2 | City |
| Montague | 5 | 1,145 | 1,220 | -1.04% | 644 | 2 | City |
| Tulelake | 6 | 821 | 896 | -1.44% | 2,002 | 0 | City |
| Dorris | 7 | 793 | 856 | -1.25% | 1,130 | 1 | City |
| Fort Jones | 8 | 651 | 702 | -1.21% | 1,081 | 1 | City |
| Etna | 9 | 623 | 673 | -1.27% | 813 | 1 | City |
Yreka is the largest city in Siskiyou County, with a population of 7,693.
Etna is the smallest city in Siskiyou County, with a population of 623.
There are 9 cities in Siskiyou County, California.