31 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Santa Rosa | 1 | 174,435 | 177,959 | -0.4% | 4,101 | 43 | City |
| Petaluma | 2 | 58,178 | 59,733 | -0.53% | 4,036 | 14 | City |
| Rohnert Park | 3 | 44,598 | 44,467 | 0.06% | 6,121 | 7 | City |
| Windsor | 4 | 25,486 | 26,340 | -0.67% | 3,427 | 7 | Town |
| Healdsburg | 5 | 10,997 | 11,346 | -0.63% | 2,488 | 4 | City |
| Sonoma | 6 | 10,545 | 10,729 | -0.35% | 3,843 | 3 | City |
| Cloverdale | 7 | 8,699 | 9,014 | -0.72% | 2,587 | 3 | City |
| Boyes Hot Springs | 8 | 7,553 | 8,006 | 0.79% | 7,125 | 1 | CDP |
| Larkfield-Wikiup | 9 | 7,389 | 8,080 | -1.34% | 1,392 | 5 | CDP |
| Cotati | 10 | 7,323 | 7,590 | -0.72% | 3,908 | 2 | City |
| Sebastopol | 11 | 7,290 | 7,515 | -0.61% | 3,874 | 2 | City |
| Guerneville | 12 | 4,822 | 4,747 | 0.42% | 497 | 10 | CDP |
| Forestville | 13 | 3,717 | 3,788 | 0.79% | 707 | 5 | CDP |
| El Verano | 14 | 2,762 | 3,256 | -3.16% | 2,412 | 1 | CDP |
| Sonoma State University | 15 | 2,134 | 1,407 | 7.13% | 5,118 | 0 | CDP |
| Penngrove | 16 | 2,100 | 2,368 | -1.32% | 521 | 4 | CDP |
| Graton | 17 | 1,662 | 1,743 | -0.18% | 1,053 | 2 | CDP |
| Bodega Bay | 18 | 1,213 | 1,069 | 0.75% | 145 | 8 | CDP |
| Sea Ranch | 19 | 1,204 | 1,156 | -0.5% | 75 | 16 | CDP |
| Glen Ellen | 20 | 1,052 | 1,214 | 1.74% | 501 | 2 | CDP |
| Occidental | 21 | 1,048 | 876 | -0.38% | 211 | 5 | CDP |
| Geyserville | 22 | 831 | 671 | -0.24% | 184 | 5 | CDP |
| Fulton | 23 | 801 | 413 | 2.17% | 411 | 2 | CDP |
| Monte Rio | 24 | 676 | 1,023 | -4.52% | 355 | 2 | CDP |
| Bodega | 25 | 629 | 590 | 4.49% | 217 | 3 | CDP |
| Eldridge | 26 | 604 | 960 | -6.5% | 926 | 1 | CDP |
| Kenwood | 27 | 504 | 540 | -6.49% | 98 | 5 | CDP |
| Cazadero | 28 | 435 | 340 | 1.16% | 61 | 7 | CDP |
| Timber Cove | 29 | 253 | 107 | 2.43% | 45 | 6 | CDP |
| Sereno Mar | 30 | 91 | 57 | -2.15% | 123 | 1 | CDP |
| Salmon Creek | 31 | 10 | 20 | 11.11% | 9 | 1 | CDP |
Santa Rosa is the largest city in Sonoma County, with a population of 174,435.
Salmon Creek is the smallest city in Sonoma County, with a population of 10.
There are 31 cities in Sonoma County, California.