South Beach, FL has a population of 3,325 and is the 8,298th largest city in the United States. The population density is 1,224 per sq mi which is 317% higher than the Florida average and 1250% higher than the national average. The median age in South Beach is 68 which is approximately 64% higher than the Florida average of 42. In South Beach, 83% of the population over 15 years of age are married, 95% speak English and 2% speak Spanish. 18% of South Beach residents were born in Florida, 77% were born out of state, 2% were born outside of the United States and 3% were foreign born.