Black Diamond, FL has a population of 1,199 and is the 14,038th largest city in the United States. The population density is 304 per sq mi which is 4% higher than the Florida average and 236% higher than the national average. The median age in Black Diamond is 53 which is approximately 28% higher than the Florida average of 42. In Black Diamond, 78% of the population over 15 years of age are married, 95% speak English and 0% speak Spanish. 18% of Black Diamond residents were born in Florida, 72% were born out of state, 0% were born outside of the United States and 11% were foreign born.