Discovery Bay, California is located in Contra Costa County. Below is a market update video for Contra Costa County. For detailed market report of your neighborhood, please contact us. Discovery Bay is a census-designated place (CDP) in eastern Contra Costa County, California in the United States, about 60 miles (97 km) from San Francisco. It is located in the East Bay region of the San Francisco Bay Area. As of 2010, its population was 13,352, a 48.7 percent gain from 8,981 at the 2000 census. Discovery Bay is a waterfront community built on a network of man-made dikes, surrounded by freshwater, except for the southeast quadrant, which comprises the golf course of Discovery Bay Country Club. Many homes have private docks with access to the Sacramento-San Joaquin River Delta. Road access is via California State Route 4.