Calabasas is a city in the southwestern region of the San Fernando Valley in Los Angeles County, California, United States. Situated between t…Calabasas is a city in the southwestern region of the San Fernando Valley in Los Angeles County, California, United States. Situated between the foothills of the Santa Monica and Santa Susana mountains, 29.9 miles northwest of downtown Los Angeles, Calabasas has a population of 22,491.