Larkspur is a city in Marin County, California, United States. Larkspur is located directly south of Kentfield and 3 miles (4.8 km) south of San Rafael, at an elevation of 43 feet (13 m). As of the 2020 census, the city's population was 13,064. Larkspur's Police Department is shared with that of the neighboring Corte Madera and town of San Anselmo as the Central Marin Police Authority.