Milpitas is a city in Santa Clara County, California, part of Silicon Valley and the broader San Francisco Bay Area. Located on the eastern sh…Milpitas is a city in Santa Clara County, California, part of Silicon Valley and the broader San Francisco Bay Area. Located on the eastern shore of San Francisco Bay, it is bordered by San Jose to the south, Fremont to the north, and the Coyote Creek and Calaveras Reservoir to the west. As of the 2020 census, the city population was 80,273. The city is located at the junction of Interstates 680 and 880 and is served by the Milpitas BART station.