Hermosa Beach is a beachfront city in Los Angeles County in the U.S. state of California, United States. Its population was 19,728 at the 2020 U.S. Census. The city is located in the South Bay region of the Greater Los Angeles area; it is one of the three Beach Cities. Hermosa Beach is bordered by the other two, Manhattan Beach to the north and Redondo Beach to the south and east.

The South Bay is a region of the Los Angeles metropolitan area, located in the southwest corner of Los Angeles County. The name stems from its geographic location stretching along the southern shore of Santa Monica Bay. The South Bay contains sixteen cities plus portions of the City of Los Angeles and unincorporated portions of the county. The area is bounded by the Pacific Ocean on the south and west and generally by the City of Los Angeles on the north and east.