Diamond Springs, CA has a population of 12,002 and is the 3,418th largest city in the United States. The population density is 721 per sq mi which is 210% higher than the California average and 696% higher than the national average. The median age in Diamond Springs is 47 which is approximately 30% higher than the California average of 36. In Diamond Springs, 58% of the population over 15 years of age are married, 91% speak English and 6% speak Spanish. 66% of Diamond Springs residents were born in California, 26% were born out of state, 1% were born outside of the United States and 7% were foreign born.