Sacramento County is a county located in the U.S. state of California. As of the 2020 census, the population was 1,585,055. Its county seat is Sacramento, which has been the state capital of California since 1854. Sacramento County is the central county of the Greater Sacramento metropolitan area. The county covers about 994 square miles (2,570 km2) in the northern portion of the Central Valley, on into Gold Country. Sacramento County extends from the low delta lands between the Sacramento River and San Joaquin River, including Suisun Bay, north to about ten miles (16 km) beyond the State Capitol and east into the foothills of the Sierra Nevada Mountains. The southernmost portion of Sacramento County has direct access to San Francisco Bay. 4K Resolution.