Grover Beach is a city in San Luis Obispo County, California, United States. The population was 12,701 at the 2020 census, down from 1…Grover Beach is a city in San Luis Obispo County, California, United States. The population was 12,701 at the 2020 census, down from 13,156 in 2010. Grover Beach is the location of the Pacific Crossing 1 cable landing station, where trans-pacific submarine communications cables come ashore and connect to the North American telecommunication network.