Barstow is a city in San Bernardino County, California, in the Mojave Desert of Southern California. Located in the Inland Empire region of California, the population was 25,415 at the 2020 census. Barstow is an important crossroads for the Inland Empire and home to Marine Corps Logistics Base Barstow.

San Bernardino County, officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181,654, making it the fifth-most populous county in California and the 14th-most populous in the United States. The county seat is San Bernardino.