Rancho Santa Margarita, CA has a population of 49,038 and is the 839th largest city in the United States. The population density is 3,803 per sq mi which is 1536% higher than the California average and 4097% higher than the national average. The median age in Rancho Santa Margarita is 37 which is approximately 2% higher than the California average of 36. In Rancho Santa Margarita, 62% of the population over 15 years of age are married, 77% speak English and 12% speak Spanish. 58% of Rancho Santa Margarita residents were born in California, 24% were born out of state, 1% were born outside of the United States and 17% were foreign born.