5 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Napa | 1 | 75,711 | 79,341 | -0.79% | 4,195 | 18 | City |
| American Canyon | 2 | 21,714 | 21,798 | -0.06% | 3,574 | 6 | City |
| St. Helena | 3 | 5,174 | 5,423 | -0.79% | 1,044 | 5 | City |
| Calistoga | 4 | 4,922 | 5,222 | -1.01% | 1,908 | 3 | City |
| Yountville | 5 | 3,207 | 3,426 | -1.11% | 2,152 | 1 | City |
Napa is the largest city in Napa County, with a population of 75,711.
Yountville is the smallest city in Napa County, with a population of 3,207.
There are 5 cities in Napa County, California.