Foster City is an affluent planned city located in San Mateo County, California, 94404. As of the 2000 census, the city had a total population of 28,803. Foster City is sometimes considered to be part of Silicon Valley for its local industry and its neighboring Silicon Valley cities. Foster City was founded in the 1960s on engineered landfill in the marshes of the San Francisco Bay, on the east edge of San Mateo. The city was named after T. Jack Foster, a real estate magnate who owned much of the land comprising the city and who was instrumental in the initial design. His successor firm, Foster Enterprises, run by his descendants, is still active in real estate affairs throughout the San Francisco Bay area.