Fair Oaks, CA has a population of 31,804 and is the 1,338th largest city in the United States. The population density is 2,943 per sq mi which is 1167% higher than the California average and 3149% higher than the national average. The median age in Fair Oaks is 46 which is approximately 29% higher than the California average of 36. In Fair Oaks, 61% of the population over 15 years of age are married, 85% speak English and 5% speak Spanish. 61% of Fair Oaks residents were born in California, 27% were born out of state, 1% were born outside of the United States and 12% were foreign born.