South Whittier, CA has a population of 59,313 and is the 659th largest city in the United States. The population density is 11,113 per sq mi which is 4682% higher than the California average and 12166% higher than the national average. The median age in South Whittier is 33 which is approximately 8% lower than the California average of 36. In South Whittier, 52% of the population over 15 years of age are married, 43% speak English and 53% speak Spanish. 66% of South Whittier residents were born in California, 8% were born out of state, 1% were born outside of the United States and 26% were foreign born.