Lauderdale-by-the-Sea, FL has a population of 6,375 and is the 5,539th largest city in the United States. The population density is 7,306 per sq mi which is 2388% higher than the Florida average and 7964% higher than the national average. The median age in Lauderdale-by-the-Sea is 59 which is approximately 42% higher than the Florida average of 42. In Lauderdale-by-the-Sea, 58% of the population over 15 years of age are married, 80% speak English and 8% speak Spanish. 13% of Lauderdale-by-the-Sea residents were born in Florida, 63% were born out of state, 2% were born outside of the United States and 21% were foreign born.