Fulton is a census-designated place in Sonoma County, California, United States. Fulton is just to the north of the city limits of Santa Rosa, and 7 miles north-northeast of Sebastopol. Fulton has a post office, established in 1871 and assigned ZIP code 95439. The community is named after Thomas and James Fulton, who founded the community. The population as of the 2010 U.S. Census was 541.