California State Population 2024 By County. For the most recent data available, please refer to the vintage 2023 data. The most populous counties in california are los angeles county with 9,663,345, san diego county at 3,269,973, orange county with 3,135,755, riverside county at 2,492,442, and san bernardino county with 2,195,611.

The most populous counties in california are los angeles county with 9,663,345, san diego county at 3,269,973, orange county with 3,135,755, riverside county at 2,492,442, and san bernardino county with 2,195,611. California state and county population pyramid viewer.