Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Weaverville | 1 | 3,579 | 3,308 | -0.03% | 278 | 12.9 | CDP |
| Hayfork | 2 | 3,370 | 2,586 | 2.15% | 47 | 72.1 | CDP |
| Lewiston | 3 | 2,389 | 1,481 | 3.73% | 119 | 20.0 | CDP |
| Junction City | 4 | 1,281 | 754 | 3.47% | 48 | 26.5 | CDP |
| Douglas City | 5 | 1,168 | 678 | 2.82% | 38 | 30.4 | CDP |
| Trinity Village | 6 | 627 | 248 | 3.81% | 156 | 4.0 | CDP |
| Salyer | 7 | 578 | 433 | 7.84% | 110 | 5.3 | CDP |
| Hyampom | 8 | 342 | 124 | 2.09% | 17 | 20.3 | CDP |
| Mad River | 9 | 306 | 341 | -2.55% | 9 | 35.2 | CDP |
| Coffee Creek | 10 | 288 | 187 | 1.77% | 25 | 11.5 | CDP |
| Trinity Center | 11 | 247 | 265 | -0.8% | 47 | 5.2 | CDP |
| Burnt Ranch | 12 | 219 | 185 | -2.23% | 16 | 13.4 | CDP |
| Post Mountain | 13 | 118 | 82 | 8.26% | 10 | 12.4 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Weaverville is the largest city in Trinity County.
Post Mountain is the smallest city in Trinity County.
There are 13 cities in Trinity County, California.