The South Bay is a sub region of the San
Francisco Bay Area, California, United States and is
roughly synonymous with Silicon Valley, the Santa Clara
Valley, and Santa Clara County (in general). It is the
most populous and most urbanized part of the Bay Area.
The South Bay is one of several Subregions in the Bay
Area including: San Francisco, the North Bay including
parts of the Wine Country, the Peninsula, and the East
Bay, among others.
San Jose is the largest city in the South Bay and the Bay Area.