Sunnyvale is a city located in the Santa Clara Valley in northwest Santa Clara County in the U.S. state of California. Sunnyvale lies along the historic El Camino Real and Highway 101 and is bordered by portions of San Jose to the north, Moffett Federal Airfield and NASA Ames Research Center to the northwest, Mountain View to the northwest, Los Altos to the southwest, Cupertino to the south, and Santa Clara to the east.