Santa Clara County is growing older—and losing children faster—than nearly anywhere else in California. The county’s population has not fully recovered from its pandemic-era losses, remaining 0.9% below its 2020 count as of July 2025, according to the newest U.S. Census Bureau estimates.
Older adults now make up nearly the same share of residents as children.
All data is derived from the Vintage 2025 series, with estimates released June 25 and March 26. Demographic characteristics were recorded as of July 1, 2020 through July 1, 2025—the latest released.
During 2022-2025, however, the county population saw a year-over-year increase in residents.
An increase of 6,481 residents was recorded from July 2024 to July 2025.
Births and immigration contributed to this gain, yet the increase was largely offset by people moving elsewhere in the U.S. (resulted in a net loss of 19,775 residents).
In July 2020, the county had 140,577 more children (under 18) than residents aged 65 and older. By July 2025, that gap had narrowed to only 48,468. Children now make up 18.8% of the county, while those 65 and older make up 16.3%—a gap of only about 2.5 percentage points.
The county also saw the fourth-largest population loss for children from 2020 to 2025, trailing behind Los Angeles, Orange and San Diego counties.
The county’s school-age population (ages 5-17) fell from 302,150 to 266,586, a decline of 35,564, or 11.8% over the past five years. The average decline per year was around 2.5% for the ages 5-17.
The only counties with larger declines in the school-age population were Los Angeles County and Orange County.
Now Santa Clara County’s median age is 38.4, up from 37.5 in 2020 and increasing for the past six years. The largest single-year age groups in the county in 2025 are heavily concentrated around the late 20s and early 30s.
The county’s 0.9% overall population decline since the start of the decade—a drop of 16,958 total residents—doesn’t fully capture a larger demographic shift. The Non-Hispanic Asian Alone population grew by 67,941, while the Non-Hispanic White Alone population fell by 76,203.
Asian Alone residents (includes Asians who are Hispanic) now make up a larger share of Santa Clara County’s population than in any other California county. About 842,000 residents identified as Asian Alone, accounting for 44% of the county’s population.
The county had California’s second-largest Asian Alone population, behind Los Angeles County.
In the county, 849,407 identified as White Alone; 107,820 as Two or More Races; 54,308 as Black or African American Alone; 52,110 as American Indian and Alaska Native Alone; and 8,739 as Native Hawaiian and Other Pacific Islander Alone.
The Black Alone population rose by 589 people from 2021 to 2022, and then remained almost unchanged through July 2025, fluctuating by fewer than 100 residents each year.
American Indian and Alaska Native Alone saw the largest change in residency from 2024-2025, with a loss of 781 residents — or 1.5% of the population.
The White Alone population has seen a constant decline in share of the county per year since 2020, while residents identifying as Two or More Races has seen a constant increase.
