Sunnyvale (pron.: /'s?nive?l/ or /'s?niv?l/) is a city in Santa Clara County, California, United States. It is one of the major cities that make up the Silicon Valley located in the San Francisco Bay Area. It is the seventh most populous city in the San Francisco Bay Area. As of the 2010 Census, the population was 140,095.
The city is bordered by portions of San Jose to the north, Moffett Federal Airfield to the northwest, Mountain View to the west, Los Altos to the southwest, Cupertino to the south, and Santa Clara to the east. It lies along the historic El Camino Real and Highway 101.
As part of the Silicon Valley, high-tech companies such as Maxim Integrated Products, Juniper Networks, Fortinet, Palm, Inc., AMD, NetApp, Spansion, Yahoo!, AppliedMicro and Ariba are headquartered there. Sunnyvale is also home to several aerospace/defense companies; Lockheed Martin has a major facility in Sunnyvale, and Honeywell, Northrop Grumman Electronic Systems - Marine Systems (formerly Joshua Hendy Iron Works), Finisar, and Spirent also have offices in Sunnyvale. Sunnyvale is also the home to Onizuka Air Force Station, where its main building, locally known as the Blue Cube, is its most prominent feature. The base, named for the deceased Space Shuttle Challenger astronaut Ellison Onizuka, was the primary artificial satellite control facility of the United States armed forces until August 2010.
Sunnyvale is one of the few U.S. cities to have a single unified Department of Public Safety, where all personnel are trained as firefighters, police officers, and EMTs, so they can respond to an emergency in any of the three roles.
Library services for the city are provided by the Sunnyvale Public Library, located at the Sunnyvale Civic Center.