Bartow, FL has a population of 18,501 and is the 2,356th largest city in the United States. The population density is 403 per sq mi which is 37% higher than the Florida average and 345% higher than the national average. The median age in Bartow is 36 which is approximately 13% lower than the Florida average of 42. In Bartow, 53% of the population over 15 years of age are married, 87% speak English and 11% speak Spanish. 61% of Bartow residents were born in Florida, 30% were born out of state, 3% were born outside of the United States and 7% were foreign born.