Lompoc /ˈlɒmpoʊk/ is a city in Santa Barbara County, California, United States. The city was incorporated on August 13, 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." In 1837, the Mexican government granted the land around Lompoc as the Rancho Lompoc land grant. After the United States gained control of California in the Mexican-American War, the valley was acquired by Thomas Dibblee, Albert Dibblee and William Welles Hollister, the latter of whom sold his portion to the Lompoc Valley Land Company. It is from that portion that the present-day Lompoc was established as a temperance colony. The town was originally intended to be called New Vineland, modeled after the temperance colony in New Jersey. Lompoc then became a military town with the completion of nearby Camp Cooke (now, Vandenberg Air Force Base). The city is known as the flower seed capital of the world.