Granite Bay is a census-designated place (CDP) in Placer County, California, United States. It is part of the Sacramento–Arden-Arcade–Roseville Metropolitan Statistical Area. The population was 20,402 at the 2010 census, up from 19,388 at the 2000 census. The ZIP code is 95746 or 95661. Granite Bay is a primarily residential suburb of Sacramento located just east of Roseville and west of Folsom Lake.