Santa Clara County, California

Santa Clara County is a county in California, United States, at the southern end of San Francisco Bay, about 45 miles southeast of San Francisco. It had a population of 1,936,259 at the 2020 census, an estimated 1,914,391 by 2025, and covers 1,304 square miles (3,380 km2) centred near 37°14′N 121°43′W.

San Jose is the county seat and the largest city in Northern California; its postal code is 95113 in the downtown core. The county holds 13 cities and 2 incorporated towns, plus 9 census-designated places and a scatter of unincorporated mountain and valley communities. California has no civil townships. The county runs on Pacific Time, and its FIPS code is 06085.

Towns & Villages in Santa Clara County

Santa Clara County has 15 incorporated municipalities and 9 census-designated places counted by the Census Bureau, plus smaller unincorporated communities in the hills. This is the heart of Silicon Valley, so even the “small towns” here are sizeable. CDP stands for census designated place, an unincorporated area the Census Bureau counts as one community. All populations are 2020 census figures. First, every incorporated city and town:

The county’s nine census-designated places sit mostly in unincorporated pockets around San Jose and in the Santa Cruz Mountains:

Beyond the CDPs, named unincorporated communities include Coyote and Mount Hamilton in the east and south of the county, and Holy City, Redwood Estates, Chemeketa Park, Aldercroft Heights and Sveadal in the Santa Cruz Mountains. Sargent, near the San Benito County line, survives mainly as a rail siding and ranch name. None of these has a separate census count.

A few names cause confusion. The city of Santa Clara is not the county government; the county is run from San Jose. Alviso, on the bayshore, was annexed by San Jose in 1968 but keeps its own ZIP code, 95002, and so does New Almaden, an old mining village inside San Jose’s southern city limits. Los Altos and Los Altos Hills are two separate municipalities. And the Burbank CDP here is a one-square-mile San Jose enclave, unrelated to the Los Angeles County city of the same name.

ZIP Codes

San Jose residential addresses use roughly forty ZIP codes between 95110 and 95148; 95113 covers downtown. The other principal codes are:

• 94085–94089 — Sunnyvale
• 95050, 95051, 95054 — Santa Clara
• 94040, 94041, 94043 — Mountain View
• 94301, 94303, 94304, 94306 — Palo Alto
• 95035 — Milpitas
• 95014 — Cupertino
• 95020 — Gilroy
• 95008 — Campbell
• 95037 — Morgan Hill
• 95070 — Saratoga
• 95030, 95032, 95033 — Los Gatos (95033 also serves the mountain communities)
• 94022, 94024 — Los Altos and Los Altos Hills
• 94305 — Stanford
• 95046 — San Martin
• 95002 — Alviso · 95013 — Coyote · 95140 — Mount Hamilton

Monte Sereno has no ZIP code of its own; its mail runs through Los Gatos 95030. The CDPs of Alum Rock, East Foothills, Burbank, Cambrian Park and Fruitdale deliver under San Jose codes, and Loyola under Los Altos codes.

Geography

The county is built around the Santa Clara Valley, a flat, fertile trough running southeast from the bay between two ranges: the Santa Cruz Mountains on the west and the higher, drier Diablo Range on the east. Mount Hamilton, in the Diablo Range, carries the University of California’s Lick Observatory at about 4,200 feet. Of the county’s 1,304 square miles, 1,290 are land and 14 are water. The largest lake is Anderson Reservoir near Morgan Hill; Coyote Creek and the Guadalupe River drain the valley north into the bay, which the county touches at Alviso.

Alameda County lies to the north, San Joaquin County touches the northeast corner for only a few hundred feet at Mount Boardman, and Stanislaus County runs along the east. Merced County sits to the southeast, San Benito County to the south, Santa Cruz County to the southwest, and San Mateo County to the northwest.

Demographics

Santa Clara County counted 1,936,259 residents in 2020, making it the sixth most populous county in California, and the 2025 estimate of 1,914,391 shows a slight decline since. San Jose and Sunnyvale are the two largest communities; San Jose alone holds nearly half the county. Median household income was $164,281 in 2024, against a statewide figure of $99,122 — one of the widest gaps of any US county. Density works out to about 1,501 people per square mile of land, though almost everyone lives in the valley floor cities; the Diablo Range is nearly empty.

Economy & Local Life

This is Silicon Valley’s home county. Professional, scientific and technical services employ about 190,101 people, manufacturing 161,855 — mostly semiconductors and hardware — and health care and social assistance 108,534. Apple is headquartered in Cupertino, Alphabet’s Google in Mountain View, and Nvidia, Intel and AMD in Santa Clara. Stanford University and its medical center anchor the northwest corner of the county, and the county government itself is among the largest public employers. Gilroy and San Martin, at the county’s rural southern end, still grow garlic, mushrooms and wine grapes. Levi’s Stadium in Santa Clara hosts the San Francisco 49ers, and downtown San Jose’s Christmas in the Park fills Plaza de César Chávez every December, a tradition running since the 1970s.

History

Santa Clara County was one of California’s original 27 counties, organised on 18 February 1850, months before statehood was formalised. It takes its name from Mission Santa Clara de Asís, founded in 1777 and itself named for Saint Clare of Assisi. The New Almaden quicksilver mines south of San Jose opened in the 1840s and became the most productive mercury operation in North America, supplying the Gold Rush’s ore-processing works.

For a century the valley was orchard country, promoted as the Valley of Heart’s Delight for its prune, apricot and cherry crops. The turn came in 1939, when William Hewlett and David Packard started Hewlett-Packard in a Palo Alto garage; the name Silicon Valley was coined in 1971, and electronics steadily replaced the orchards through the postwar decades.

Getting There

US 101 runs the length of the county from Palo Alto through San Jose to Gilroy. Interstates 280, 680 and 880 link San Jose with San Francisco and the East Bay, while SR 17 crosses the mountains to Santa Cruz, SR 85 and SR 87 serve the valley’s west side, and SR 152 climbs Pacheco Pass east toward Interstate 5.

• San Francisco — about 45 miles northwest
• Oakland — about 40 miles north
• Santa Cruz — about 30 miles southwest
• Sacramento — about 120 miles northeast

San Jose Mineta International Airport sits just north of downtown San Jose, with San Francisco International about 25 miles up the Peninsula from Palo Alto. Amtrak’s Coast Starlight and Capitol Corridor trains stop at San Jose Diridon Station, which also carries Caltrain to San Francisco; BART reaches the county at Milpitas and Berryessa in north San Jose.

Frequently Asked Questions

Where is Santa Clara County located?
At the southern end of San Francisco Bay in Northern California, about 45 miles southeast of San Francisco, between the Santa Cruz Mountains and the Diablo Range.

What is the population of Santa Clara County?
1,936,259 at the 2020 census, with a 2025 estimate of 1,914,391 — the sixth most populous county in California.

How big is Santa Clara County?
1,304 square miles (3,380 km2), of which 1,290 square miles are land and 14 are water.

What is the county seat of Santa Clara County?
San Jose — not the city of Santa Clara. San Jose is also the county’s and Northern California’s largest city.

How many cities and towns are in Santa Clara County?
Fifteen incorporated municipalities: 13 cities and the towns of Los Gatos and Los Altos Hills, plus nine census-designated places such as Stanford, Alum Rock and San Martin.

What ZIP codes does Santa Clara County use?
San Jose spans 95110–95148; other principal codes include 94085–94089 for Sunnyvale, 95050–95054 for Santa Clara, 94301–94306 for Palo Alto and 95020 for Gilroy.

What is Santa Clara County known for?
Silicon Valley — headquarters of Apple, Google and Nvidia — plus Stanford University, Lick Observatory on Mount Hamilton and the New Almaden mercury mines.

More counties in this state: Towns and villages in California.