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 20402 at the 2010 census up from 19388 at the 2000 census. The ZIP code is 95746. Granite Bay is a primarily residential suburb of Sacramento located just east of Roseville and west of Folsom Lake.