How many people live in San Diego County, CA?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 3.3 million people living in San Diego County, CA. That makes San Diego County the fifth-most populous county in the US. It is also the second-largest in California, accounting for 8.4% of the state’s population.
3.3M
population of San Diego County, CA (2024)
8.4%
County share of the California population (2024)
About 3.3 million people lived in San Diego County, CA in 2024.
Population estimates, 2000–2024
What are San Diego County, CA’s age demographics?
About 537,400 San Diego County residents are aged 65 and older in 2024. That represents 16.3% of its population. For comparison, the age group represents 16.6% of California’s population and 18% in the US overall.
Another 671,600 San Diego County residents, or 20.4% of the population, were children under 18. For comparison, the age group represents 21.4% of California’s population and 21.6% in the US overall.
A higher share of San Diego County, CA's population is aged 25–44 than the US as a whole.
Population estimates by age group, (2024)
What are San Diego County, CA’s racial and ethnic demographics?
Hispanic residents make up 35.2% of the San Diego County, CA population, higher than the national share of 20%. San Diego County also has a larger share of people identifying as non-Hispanic Asian (13.1%) than the US overall (6.5%).
In contrast, San Diego County’s non-Hispanic white population accounts for 42.4%, below the 57.5% nationwide, and the non-Hispanic Black or African American population makes up 4.6% of the county, compared with 12.6% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
San Diego County, CA has a higher share of a non-Hispanic white population than California as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in San Diego County, CA is San Diego with about 1.4 million residents in 2024.
Cities and towns in San Diego County, CA ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | San Diego | 1,404,452 |
| 2. | Chula Vista | 278,546 |
| 3. | Oceanside | 170,941 |
| 4. | Escondido | 148,847 |
| 5. | Carlsbad | 113,575 |
| 6. | El Cajon | 103,291 |
| 7. | Vista | 99,322 |
| 8. | San Marcos | 96,620 |
| 9. | Encinitas | 61,137 |
| 10. | La Mesa | 60,767 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
