Longboat Key, FL has a population of 7,158 and is the 5,101st largest city in the United States. The population density is 1,733 per sq mi which is 490% higher than the Florida average and 1813% higher than the national average. The median age in Longboat Key is 71 which is approximately 71% higher than the Florida average of 42. In Longboat Key, 84% of the population over 15 years of age are married, 89% speak English and 3% speak Spanish. 4% of Longboat Key residents were born in Florida, 78% were born out of state, 0% were born outside of the United States and 18% were foreign born.