The population of Native California refers to the population of Indigenous peoples of California. Estimates prior to and after European contact have varied substantially. Pre-contact estimates range from 133,000 to 705,000 with some recent scholars concluding that these estimates are low.

Following the arrival of Europeans in California, disease and violence—termed the California Genocide—reduced the population to as low as 25,000. During and after the California Gold Rush, it is estimated that miners and others killed about 4,500 Indigenous people of California between 1849 and 1870. As of 2005, California is the state with the largest self-identified Native American population according to the U.S. Census at 696,600.

Historians have calculated the Native Californian population prior to European entry into the region using a number of different methods, including:

Few analysts claim that these methods yield accurate numbers. The estimates developed by different analysts commonly vary by a factor of two or more. Stephen Powers initially estimated that the pre-contact population of the state was 1,520,000. He later reduced this figure to 705,000.

C. Hart Merriam offered the first detailed analysis. He based his estimates on mission records and extrapolated that to non-missionized areas. His estimate for the state as a whole was 260,000. Alfred L. Kroeber made a detailed re-analysis, both for the state as a whole and for the individual ethnolinguistic groups within it. He reduced Merriam's figure by about half, to 133,000 Native Californians in 1770.

Martin A. Baumhoff used an ecological basis to evaluate the potential carrying capacity and estimated an aboriginal population of 350,000.

Sherburne F. Cook was the most persistent and painstaking student of the problem, examining in detail both pre-contact estimates and the history of demographic decline during mission and post-mission periods. Initially, in 1943, Cook arrived at a figure only 7% higher than the one previously suggested by Kroeber: 133,550 (excluding the Modoc, Northern Paiute, Washoe, Owens Valley Paiute, and Colorado River Yumans). Cook later raised his estimate to 310,000.

Some scholars now believe that waves of epidemic diseases reached California well in advance of the arrival of the Franciscans in 1769. If correct, this may imply that population estimates using the beginning of the mission period as a baseline have substantially underestimated the state's pre-Columbian population.