Milpitas (Spanish for 'little milpas' or little cornfields) 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 to the west, and Calaveras Reservoir to the east. 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.

Historically inhabited by the Ohlone people, the area served as a crossroads between Mission San José de Guadalupe in present-day Fremont and Mission Santa Clara de Asis in present-day Santa Clara. The city’s modern development began in the mid-20th century, driven by postwar suburbanization and its incorporation in 1954. Milpitas experienced rapid growth during the 1970s–1990s, fueled by Silicon Valley’s tech industry, and became a hub for manufacturing and corporate offices, hosting companies like Cisco Systems, KLA Corporation, and Flex Ltd.. Its diverse population includes significant Asian and Hispanic communities, reflecting broader Bay Area demographic trends.

Milpitas' economy is closely tied to the tech sector, though it also features retail landmarks such as the Great Mall of the Bay Area, one of Northern California’s largest outlet malls. Environmental challenges include odor issues linked to the adjacent Newby Island landfill and water pollution from street water runoff and industrial wastes. The city's infrastructure includes multiple public parks, trails, and access to regional transit systems, including VTA light rail and buses.

Milpitas was first inhabited by Tamien people, a subgroup of the Ohlone people who had resided in the San Francisco Bay Area for thousands of years. The Ohlone Indians lived a traditional life based on everyday hunting and gathering. Some of the Ohlone lived in various villages within what is now Milpitas, including sites underneath what are now the Calvary Assembly of God Church and Higuera Adobe Park. Archaeological evidence gathered from Ohlone graves at the Elmwood Correctional Facility in 1993 revealed a rich trade with other tribes from Sacramento to Monterey.

During the Spanish expeditions of the late 18th century, several missions were founded in the San Francisco Bay Area. During the mission period, Milpitas served as a crossroads between Mission San José de Guadalupe in present-day Fremont and Mission Santa Clara de Asis in present-day Santa Clara. The land of modern-day Milpitas was divided between the 6,353-acre (25.71 km²) Rancho Rincon de Los Esteros (Spanish for "corner of the wetlands") granted to Ignacio Alviso; the 4,457.8-acre (18.040 km²) Rancho Milpitas (Spanish for "little milpaa" (corn fields)) granted to José María Alviso; and the 4,394.35-acre (17.7833 km²) Rancho Los Tularcitos (Spanish for "little tule marshes") granted to José Higuera. Jose Maria Alviso was the son of Francisco Xavier Alviso and Maria Bojorquez, both of whom arrived in San Francisco as children with the de Anza Expedition. José María Alviso is considered to be the founder of Milpitas. Due to Jose Maria Alviso's descendants' difficulty securing his claims to the Rancho Milpitas property, portions of his land were either swindled from the Alviso family or were sold to American settlers to pay for legal fees.

Both landowners had built prominent adobe homes on their properties. Today, both adobes still exist and are the oldest structures in Milpitas. The seriously eroded walls of the Jose Higuera Adobe, now in Higuera Adobe Park, are encapsulated in a brick shell built c. 1970 by Marian Weller, a descendant of pioneer Joseph Weller.

The Alviso Adobe can be seen mostly in its original form, with one kitchen addition made by the Cuciz family after they purchased the adobe from the Gleason family in 1922. Prior to the city acquiring the Alviso Adobe in 1995, it was the oldest continuously occupied adobe house in California dating from the Mexican period and today is still gradually being restored and undergoing seismic upgrades by the City of Milpitas.

In the 1850s, large numbers of Americans of English, German, and Irish descent arrived to farm the fertile lands of Milpitas. The Burnett, Rose, Dempsey, Jacklin, Trimble, Ayer, Parks, Wool, Weller, Minnis, and Evans families are among the early settlers of Milpitas. (Today many schools, streets, and parks have been named in honor of these families.) These early settlers farmed the land that was once the ranchos. Some set up businesses on what was then called Mission Road (now called Main Street) between Calaveras Road (now called Carlo Street) and the Alviso-Milpitas Road (now called Serra Way). By the late 20th century this area became known as the "Midtown" district. Yet another influx of immigration came in the 1870s and 1880s as Portuguese sharecroppers from the Azores came to farm the Milpitas hillsides. Many of the Azoreans had such locally well-known surnames as Coelho, Covo, Mattos, Nunes, Spangler, Serpa, and Silva.