Mission Viejo, CA has a population of 96,178 and is the 325th largest city in the United States. The population density is 5,434 per sq mi which is 2239% higher than the California average and 5898% higher than the national average. The median age in Mission Viejo is 44 which is approximately 23% higher than the California average of 36. In Mission Viejo, 64% of the population over 15 years of age are married, 76% speak English and 9% speak Spanish. 52% of Mission Viejo residents were born in California, 27% were born out of state, 1% were born outside of the United States and 20% were foreign born.