| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| San Diego | 1 | 1,410,522 | 1,382,566 | 0.31% | 4,326 | 326 | City |
| Chula Vista | 2 | 275,767 | 275,809 | 0.08% | 5,556 | 50 | City |
| Oceanside | 3 | 169,666 | 174,064 | -0.48% | 4,111 | 41 | City |
| Escondido | 4 | 145,251 | 150,974 | -0.53% | 3,889 | 37 | City |
| Carlsbad | 5 | 111,835 | 114,924 | -0.38% | 2,958 | 38 | City |
| El Cajon | 6 | 100,948 | 106,069 | -0.79% | 6,957 | 15 | City |
| Vista | 7 | 98,294 | 98,838 | 0.02% | 5,181 | 19 | City |
| San Marcos | 8 | 95,057 | 94,927 | 0.16% | 3,869 | 25 | City |
| Encinitas | 9 | 60,487 | 61,997 | -0.41% | 3,174 | 19 | City |
| La Mesa | 10 | 59,754 | 61,100 | -0.27% | 6,572 | 9 | City |
| Santee | 11 | 57,953 | 59,861 | -0.43% | 3,504 | 17 | City |
| National City | 12 | 56,971 | 61,454 | -1.45% | 7,757 | 7 | City |
| Poway | 13 | 49,254 | 48,784 | 0.15% | 1,260 | 39 | City |
| Lemon Grove | 14 | 27,957 | 27,770 | 0.08% | 7,207 | 4 | City |
| Imperial Beach | 15 | 25,048 | 26,055 | -0.63% | 5,836 | 4 | City |
| Coronado | 16 | 20,573 | 22,435 | -2.47% | 2,538 | 8 | City |
| Solana Beach | 17 | 12,556 | 12,927 | -0.37% | 3,678 | 3 | City |
| Del Mar | 18 | 3,842 | 3,944 | -0.41% | 2,238 | 2 | City |
San Diego is the largest city in San Diego County, with a population of 1,410,522.
Del Mar is the smallest city in San Diego County, with a population of 3,842.
There are 18 cities in San Diego County, California.