| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| San Rafael | 1 | 59,079 | 61,140 | -0.56% | 3,562 | 17 | City |
| Novato | 2 | 51,706 | 53,143 | -0.46% | 1,889 | 27 | City |
| Mill Valley | 3 | 13,716 | 14,206 | -0.6% | 2,868 | 5 | City |
| Larkspur | 4 | 12,545 | 13,035 | -0.59% | 4,183 | 3 | City |
| San Anselmo | 5 | 12,504 | 12,809 | -0.41% | 4,674 | 3 | Town |
| Corte Madera | 6 | 9,874 | 10,202 | -0.55% | 3,125 | 3 | Town |
| Tiburon | 7 | 8,826 | 9,143 | -0.62% | 1,966 | 4 | Town |
| Fairfax | 8 | 7,383 | 7,592 | -0.46% | 3,314 | 2 | Town |
| Sausalito | 9 | 6,970 | 7,256 | -0.7% | 3,951 | 2 | City |
| Ross | 10 | 2,296 | 2,334 | -0.35% | 1,474 | 2 | Town |
| Belvedere | 11 | 2,053 | 2,127 | -0.63% | 3,956 | 1 | City |
San Rafael is the largest city in Marin County, with a population of 59,079.
Belvedere is the smallest city in Marin County, with a population of 2,053.
There are 11 cities in Marin County, California.