| Isla San Diego | |
| Location: | Baja California Sur |
| Coordinates: | 25.2003°N -110.6981°W |
| Waterbody: | Gulf of California |
| Area Km2: | 0.563 |
| Length Km: | 1.5 |
| Width M: | 500 |
| Country: | Mexico  |
| Population: | Uninhabited |
Isla San Diego is a small island in Mexico in the southern Gulf of California. Administratively it belongs to the municipality of Comondú of the State of Baja California Sur and is very close to the small island called Isla La Habana.
It is barren and uninhabited, is located about 221NaN1 east of the coast of Baja California, 9.51NaN1 north of San Jose Island and 61NaN1 south-southeast of the island of Santa Cruz. Isla San Diego is 1.52NaN2 long, up to 5001NaN1 wide and has an area of 0.5631NaN1.