Thousand Oaks, CA has a population of 128,623 and is the 210th largest city in the United States. The population density is 2,328 per sq mi which is 902% higher than the California average and 2469% higher than the national average. The median age in Thousand Oaks is 43 which is approximately 19% higher than the California average of 36. In Thousand Oaks, 60% of the population over 15 years of age are married, 76% speak English and 12% speak Spanish. 52% of Thousand Oaks residents were born in California, 28% were born out of state, 1% were born outside of the United States and 19% were foreign born.