South San Gabriel, CA has a population of 8,725 and is the 4,369th largest city in the United States. The population density is 10,472 per sq mi which is 4406% higher than the California average and 11459% higher than the national average. The median age in South San Gabriel is 45 which is approximately 26% higher than the California average of 36. In South San Gabriel, 58% of the population over 15 years of age are married, 23% speak English and 28% speak Spanish. 44% of South San Gabriel residents were born in California, 6% were born out of state, 1% were born outside of the United States and 50% were foreign born.