17 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Napa | 1 | 76,316 | 79,305 | -0.79% | 4,229 | 18 | City |
| Napa | 2 | 76,316 | 79,341 | -0.79% | 4,229 | 18 | City |
| American Canyon | 3 | 21,728 | 21,839 | -0.06% | 3,576 | 6 | City |
| American Canyon | 4 | 21,728 | 21,798 | -0.06% | 3,576 | 6 | City |
| St. Helena | 5 | 5,215 | 5,432 | -0.8% | 1,052 | 5 | City |
| St. Helena | 6 | 5,215 | 5,423 | -0.8% | 1,052 | 5 | City |
| Calistoga | 7 | 4,972 | 5,228 | -1% | 1,928 | 3 | City |
| Calistoga | 8 | 4,972 | 5,222 | -1% | 1,928 | 3 | City |
| Fetters Hot Springs-Agua Caliente | 9 | 4,244 | 3,554 | 0.17% | 2,905 | 1 | CDP |
| Yountville | 10 | 3,243 | 3,427 | -1.13% | 2,177 | 1 | City |
| Yountville | 11 | 3,243 | 3,426 | -1.13% | 2,177 | 1 | City |
| Angwin | 12 | 2,651 | 3,415 | -1.01% | 549 | 5 | CDP |
| Temelec | 13 | 1,756 | 1,915 | 1.21% | 1,106 | 2 | CDP |
| Silverado Resort | 14 | 991 | 1,171 | -0.7% | 524 | 2 | CDP |
| Deer Park | 15 | 727 | 772 | -4.72% | 129 | 6 | CDP |
| Moskowite Corner | 16 | 130 | 69 | -3.7% | 46 | 3 | CDP |
| Rutherford | 17 | 103 | 100 | -3.74% | 61 | 2 | CDP |
Napa is the largest city in Napa County, with a population of 76,316.
Rutherford is the smallest city in Napa County, with a population of 103.
There are 17 cities in Napa County, California.