Ashland is a census-designated place and unincorporated community in Alameda County, California, United States. The population was 23,823 at the 2020 census. Ashland is located between the city of San Leandro to the north, the unincorporated community of Cherryland to the south, the unincorporated community of Castro Valley to the east, and the unincorporated community of San Lorenzo to the southwest.