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 21,247 at the 2020 census, up from 20,402 at the 2010 census. Granite Bay is a primarily residential suburb of Sacramento and is located just east of Roseville and west of Folsom Lake.