Lompoc /ˈlɒmpoʊk/ LOM-pohk is a city in Santa Barbara County, California, United States. The city was incorporated in 1888. The population was 42,434 at the 2010 census, up from 41,103 at the 2000 census. Prior to the European settlements, the area around Lompoc was inhabited by the Chumash. The name of the city is derived from a Chumash word "Lum Poc" that means "stagnant waters" or "lagoon. " The Spanish called it "lumpoco.