Interlachen, FL has a population of 1,686 and is the 12,023rd largest city in the United States. The population density is 286 per sq mi which is 3% lower than the Florida average and 215% higher than the national average. The median age in Interlachen is 36 which is approximately 15% lower than the Florida average of 42. In Interlachen, 50% of the population over 15 years of age are married, 91% speak English and 9% speak Spanish. 53% of Interlachen residents were born in Florida, 39% were born out of state, 6% were born outside of the United States and 2% were foreign born.