The Getty Fire started near the Getty Center arts complex and spread to about 500 acres (202 ha), close to some of the city's most expensive homes.
California's governor has declared a state-wide emergency as wildfires continue to rage in many other areas.
NBA star Lebron James was among those forced to flee the LA fire.
LA Mayor Eric Garcetti announced he would sign an emergency declaration to draw more resources to fight the Getty fire.
Some 3,300 homes are in the mandatory evacuation zone.