Calabasas is a city in Los Angeles County, California, in the western United States. As of the 2000 census, the city population was 23,123. The city was formally incorporated in 1991. Many parts of Calabasas are mountains or hills, which have spectacular views of the San Fernando Valley. Many of the neighborhoods in Calabasas are gated communities comprised of large houses. The city covers territory in both the San Fernando Valley and the Conejo Valley.

An extensive 2006 Secondhand Smoke Control Ordinance caused the city to receive international attention.

Leonis Adobe, the adobe structure on 23537 Calabasas Road, dates from 1844 and is one of the oldest buildings in the greater LA area.