Silicon Valley is located in the northern part of the U.S. state of California.
The Santa Clara Valley runs south-southeast from the southern end of San Francisco Bay in Northern California in the United States . Silicon Valley is a nickname for the southern portion of the San Francisco Bay Area , in the northern part of the U.S. state of California . As more high-tech companies were established across the Santa Clara Valley , and then north towards the Bay Area 's two other major cities , San Francisco and Oakland , the `` Silicon Valley '' name eventually came to refer to all high-tech businesses in the region .