Ocean Beach lies on the Pacific Ocean at the estuary of the San Diego River, at the western terminus of Interstate 8. Located about 7 mi (11 km) northwest of Downtown San Diego, it sits south of Mission Bay and Mission Beach and directly north of Point Loma. The O.B. community planning area comprises about 1 square mile (742 acres),  bounded on the north by the San Diego River, on the west by the Pacific Ocean, on the east by Froude St., Seaside St. and West Point Loma Boulevard, and on the south by Adair Street.

Prior to European contact, the Kumeyaay people inhabited Ocean Beach and had established the fishing encampment of Hapai. The Kumeyaay visited the area to conduct fishing and food processing operations, as mussels, clams, abalone, and lobsters were harvested from the area.

The beach’s initial name was Mussel Beach, for the mussels available there. Its current name, Ocean Beach, was given in 1887 by developers Billy Carlson and Albert E. Higgins