Shelter Island is a neighborhood of Point Loma in San Diego, California, United States. It is actually not an island but is connected to the mainland by a narrow strip of land. It was originally a sandbank in San Diego Bay, visible only at low tide. It was built up into dry land using material dredged from the bay in 1934. It was developed in the 1950s and contains hotels, restaurants, marinas, and public parkland.

San Diego Bay is a natural harbor and deepwater port located in San Diego County, California near the U.S.–Mexico border. The bay, which is 12 miles (19 km) long and 1 to 3 miles wide, is the third largest of the three large, protected natural bays on California's 840 miles (1,350 km) of coastline, after San Francisco Bay and Humboldt Bay. The highly urbanized land adjacent to the bay includes the city of San Diego and four other cities: National City, Chula Vista, Imperial Beach and Coronado.