Key West, FL has a population of 26,039 and is the 1,656th largest city in the United States. The population density is 4,650 per sq mi which is 1484% higher than the Florida average and 5032% higher than the national average. The median age in Key West is 41 which is approximately 2% lower than the Florida average of 42. In Key West, 46% of the population over 15 years of age are married, 76% speak English and 16% speak Spanish. 32% of Key West residents were born in Florida, 47% were born out of state, 3% were born outside of the United States and 19% were foreign born.