Lake Buena Vista, FL has a population of 3 and is the 29,070th largest city in the United States. The population density is 1 per sq mi which is 100% lower than the Florida average and 99% lower than the national average. The median age in Lake Buena Vista is 0 which is approximately 100% lower than the Florida average of 42. In Lake Buena Vista, 100% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 0% of Lake Buena Vista residents were born in Florida, 100% were born out of state, 0% were born outside of the United States and 0% were foreign born.