Fair Oaks is a census-designated place (CDP) in Sacramento County California United States. It is part of the Sacramento–Arden-Arcade–Roseville Metropolitan Statistical Area. The population was 30912 at the 2010 census up from 28008 at the 2000 census. Fair Oaks’s zip code is 95628 and its area code is . Fair Oaks is bounded on the south side by the American River and Rancho Cordova on the north side by the city of Citrus Heights on the west side by Carmichael and the east side by Orangevale. Fair Oaks is known for its mix of suburban and semi-rural neighborhoods.