Santa Margarita, CA has a population of 1,346 and is the 13,338th largest city in the United States. The population density is 2,602 per sq mi which is 1019% higher than the California average and 2771% higher than the national average. The median age in Santa Margarita is 52 which is approximately 45% higher than the California average of 36. In Santa Margarita, 54% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 75% of Santa Margarita residents were born in California, 24% were born out of state, 0% were born outside of the United States and 1% were foreign born.