22 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Ukiah | 1 | 15,751 | 16,553 | -1.01% | 3,304 | 5 | City |
| Fort Bragg | 2 | 6,881 | 6,975 | -0.28% | 2,382 | 3 | City |
| Willits | 3 | 4,752 | 4,979 | -0.94% | 1,681 | 3 | City |
| Brooktrails | 4 | 4,741 | 4,559 | 2.15% | 653 | 7 | CDP |
| Redwood Valley | 5 | 1,597 | 1,812 | -0.5% | 582 | 3 | CDP |
| Covelo | 6 | 1,385 | 1,352 | 0.65% | 195 | 7 | CDP |
| Hopland | 7 | 1,092 | 899 | 2.06% | 310 | 4 | CDP |
| Talmage | 8 | 1,006 | 1,136 | -0.79% | 633 | 2 | CDP |
| Boonville | 9 | 985 | 997 | -0.3% | 178 | 6 | CDP |
| Cleone | 10 | 813 | 841 | 1.63% | 510 | 2 | CDP |
| Mendocino | 11 | 690 | 707 | -1.99% | 306 | 2 | CDP |
| Calpella | 12 | 673 | 620 | 0% | 264 | 3 | CDP |
| Potter Valley | 13 | 510 | 374 | -1.73% | 127 | 4 | CDP |
| Point Arena | 14 | 443 | 463 | -0.89% | 324 | 1 | City |
| Laytonville | 15 | 383 | 777 | -12.95% | 71 | 5 | CDP |
| Anchor Bay | 16 | 376 | 326 | 0.53% | 107 | 4 | CDP |
| Manchester | 17 | 324 | 267 | 2.86% | 124 | 3 | CDP |
| Caspar | 18 | 323 | 307 | -3.58% | 108 | 3 | CDP |
| Little River | 19 | 250 | 176 | 3.73% | 150 | 2 | CDP |
| Albion | 20 | 236 | 289 | 2.16% | 130 | 2 | CDP |
| Comptche | 21 | 120 | 142 | -2.44% | 104 | 1 | CDP |
| Leggett | 22 | 27 | 56 | -18.18% | 10 | 3 | CDP |
Ukiah is the largest city in Mendocino County, with a population of 15,751.
Leggett is the smallest city in Mendocino County, with a population of 27.
There are 22 cities in Mendocino County, California.