Macclenny, FL has a population of 6,451 and is the 5,496th largest city in the United States. The population density is 1,363 per sq mi which is 364% higher than the Florida average and 1405% higher than the national average. The median age in Macclenny is 35 which is approximately 15% lower than the Florida average of 42. In Macclenny, 52% of the population over 15 years of age are married, 95% speak English and 2% speak Spanish. 68% of Macclenny residents were born in Florida, 27% were born out of state, 1% were born outside of the United States and 3% were foreign born.