Elkhorn is an unincorporated community and census-designated place in Monterey County, California, United States. Elkhorn was originally a stop on the Southern Pacific Railroad 4 miles north of Castroville, at an elevation of 10 feet. The settled part of the community now occupies the hills to the east of the railroad. The population of the Elkhorn CDP was 1,588 at the 2020 census. Local understandings of the extent of Elkhorn may vary from the Census definition.