Atlantic Beach, FL has a population of 13,089 and is the 3,187th largest city in the United States. The population density is 3,734 per sq mi which is 1172% higher than the Florida average and 4022% higher than the national average. The median age in Atlantic Beach is 46 which is approximately 11% higher than the Florida average of 42. In Atlantic Beach, 53% of the population over 15 years of age are married, 91% speak English and 5% speak Spanish. 39% of Atlantic Beach residents were born in Florida, 52% were born out of state, 3% were born outside of the United States and 6% were foreign born.