Lancaster is a charter city in northern Los Angeles County, in the Antelope Valley of the western Mojave Desert in Southern California. As of the 2010 census it had a population of 156,633, and in 2019 the population was estimated at 157,601, making Lancaster the 33rd largest city in California. Lancaster is part of a twin city complex with its southern neighbor Palmdale, and together they are the principal cities within the Antelope Valley region.
Lancaster is located approximately 70 miles north of downtown Los Angeles, and is near the Kern County line. It is separated from the Los Angeles Basin by the San Gabriel Mountains to the south, and from Bakersfield and the San Joaquin Valley by the Tehachapi Mountains to the north. The population of Lancaster has grown from 37,000 at the time of its incorporation in 1977 to over 157,000 as of 2019.