Topanga is a census-designated place (CDP) in western Los Angeles County, California, United States. Located in the Santa Monica Mountains, the community exists in Topanga Canyon and the surrounding hills. The narrow southern portion of Topanga at the coast is between the city of Malibu and the Los Angeles neighborhood of Pacific Palisades. As of the 2010 census the population of the Topanga CDP was 8,289. The ZIP code is 90290 and the area code is primarily 310, with 818 only at the north end of the canyon. It is in the 3rd County Supervisorial district.
Topanga is the name given to the area by the Native American indigenous Tongva tribe, and may mean "where the mountain meets the sea" or "a place above." The name in the Tongva language, Topaa'nga, has a root topaa'- that likely comes from the Chumash language. It was the western border of their territory, abutting the Chumash tribe that occupied the coast from Malibu northwards. Bedrock mortars can be found carved into rock outcroppings in many locations.
Topanga was first settled by Europeans in 1839.