San Gregorio is an unincorporated community in San Mateo County, California, with a population of 214 people. It is located in the San Francisco Bay Area, south of Half Moon Bay. Just east of Highway 1, it is one mile (1.6 km) inland on Highway 84, from San Gregorio State Beach. It is also located 7 miles (11 km) north of Pescadero via Stage Road and 8 miles (13 km) west of La Honda via SR 84.

Half Moon Bay is a coastal city in San Mateo County, California, United States, approximately 25 miles south of San Francisco. Its population was 11,795 as of the 2020 census. Immediately north of Half Moon Bay is Pillar Point Harbor and the unincorporated community of Princeton-by-the-Sea. Half Moon Bay is known for Mavericks, a big-wave surf location. It is called Half Moon Bay because of its crescent shape.