Lake Mary, FL has a population of 15,478 and is the 2,757th largest city in the United States. The population density is 1,690 per sq mi which is 476% higher than the Florida average and 1765% higher than the national average. The median age in Lake Mary is 46 which is approximately 10% higher than the Florida average of 42. In Lake Mary, 67% of the population over 15 years of age are married, 83% speak English and 8% speak Spanish. 31% of Lake Mary residents were born in Florida, 52% were born out of state, 3% were born outside of the United States and 14% were foreign born.