7 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| San Luis Obispo | 1 | 50,363 | 47,191 | 1.27% | 3,692 | 14 | City |
| El Paso de Robles (Paso Robles) | 2 | 31,587 | 31,489 | 0.06% | 1,586 | 20 | City |
| Atascadero | 3 | 29,742 | 29,746 | 0% | 1,141 | 26 | City |
| Arroyo Grande | 4 | 18,202 | 18,436 | -0.26% | 3,065 | 6 | City |
| Grover Beach | 5 | 12,500 | 12,668 | -0.27% | 5,407 | 2 | City |
| Morro Bay | 6 | 10,548 | 10,761 | -0.41% | 1,976 | 5 | City |
| Pismo Beach | 7 | 7,964 | 8,063 | -0.25% | 2,277 | 3 | City |
San Luis Obispo is the largest city in San Luis Obispo County, with a population of 50,363.
Pismo Beach is the smallest city in San Luis Obispo County, with a population of 7,964.
There are 7 cities in San Luis Obispo County, California.