California Population By County in 2015

Based on the US Census Vintage data estimates, in 2015, the population of California was 38,904,296. Among all California counties, Los Angeles had the highest population (10,077,263), followed by San Diego (3,280,825), and Orange (3,148,952). Alpine was the least populated county (1,080).

Hover over or click on the counties in the map below to see the populations. The data can also be found in a table below. You can use the table to sort, filter, and explore the data further.

You can see similar information for other states and by state for the United States.