St. Augustine Beach, FL has a population of 6,710 and is the 5,331st largest city in the United States. The population density is 3,168 per sq mi which is 979% higher than the Florida average and 3397% higher than the national average. The median age in St. Augustine Beach is 50 which is approximately 21% higher than the Florida average of 42. In St. Augustine Beach, 69% of the population over 15 years of age are married, 89% speak English and 4% speak Spanish. 30% of St. Augustine Beach residents were born in Florida, 58% were born out of state, 1% were born outside of the United States and 11% were foreign born.