7 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| San Luis Obispo | 1 | 50,998 | 47,191 | 1.26% | 3,739 | 14 | City |
| El Paso de Robles (Paso Robles) | 2 | 31,607 | 31,489 | 0.06% | 1,587 | 20 | City |
| Atascadero | 3 | 29,741 | 29,746 | 0% | 1,141 | 26 | City |
| Arroyo Grande | 4 | 18,155 | 18,436 | -0.26% | 3,057 | 6 | City |
| Grover Beach | 5 | 12,467 | 12,668 | -0.26% | 5,392 | 2 | City |
| Morro Bay | 6 | 10,506 | 10,761 | -0.4% | 1,968 | 5 | City |
| Pismo Beach | 7 | 7,944 | 8,063 | -0.25% | 2,272 | 3 | City |
San Luis Obispo is the largest city in San Luis Obispo County, with a population of 50,998.
Pismo Beach is the smallest city in San Luis Obispo County, with a population of 7,944.
There are 7 cities in San Luis Obispo County, California.