Kentfield (formerly Ross Landing, Tamalpais, and Kent) is a census-designated place (CDP) in Marin County, California, United States, just north of San Francisco. Kentfield is located on the Northwestern Pacific Railroad  southwest of downtown San Rafael, at an elevation of 115 feet (35 m). The population was 6,485 at the 2010 census. The ZIP codes are 94904 for street addresses, and 94914 for PO boxes, and are shared with the neighboring community of Greenbrae.