5 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Napa | 1 | 76,316 | 79,341 | -0.79% | 4,229 | 18 | City |
| American Canyon | 2 | 21,728 | 21,798 | -0.06% | 3,576 | 6 | City |
| St. Helena | 3 | 5,215 | 5,423 | -0.8% | 1,052 | 5 | City |
| Calistoga | 4 | 4,972 | 5,222 | -1% | 1,928 | 3 | City |
| Yountville | 5 | 3,243 | 3,426 | -1.13% | 2,177 | 1 | City |
Napa is the largest city in Napa County, with a population of 76,316.
Yountville is the smallest city in Napa County, with a population of 3,243.
There are 5 cities in Napa County, California.