9 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Loyalton | 1 | 722 | 737 | -0.41% | 2,028 | 0.36 | City |
| Sierraville | 2 | 234 | 166 | 0.86% | 47 | 5.02 | CDP |
| Sierra City | 3 | 221 | 84 | 0% | 103 | 2.15 | CDP |
| Verdi | 4 | 82 | 154 | -5.75% | 20 | 4.17 | CDP |
| Goodyears Bar | 5 | 81 | 80 | 6.58% | 40 | 2.05 | CDP |
| Alleghany | 6 | 79 | 99 | 6.76% | 226 | 0.35 | CDP |
| Calpine | 7 | 67 | 164 | -12.99% | 94 | 0.71 | CDP |
| Downieville | 8 | 61 | 99 | -19.74% | 19 | 3.18 | CDP |
| Sattley | 9 | 34 | 73 | 6.25% | 17 | 2.05 | CDP |
Loyalton is the largest city in Sierra County, with a population of 722.
Sattley is the smallest city in Sierra County.
There are 9 cities in Sierra County, California.