Jacksonville, AL has a population of 12,827 and is the 3,241st largest city in the United States. The population density is 1,171 per sq mi which is 1173% higher than the Alabama average and 1193% higher than the national average. The median age in Jacksonville is 27 which is approximately 31% lower than the Alabama average of 39. In Jacksonville, 37% of the population over 15 years of age are married, 96% speak English and 1% speak Spanish. 61% of Jacksonville residents were born in Alabama, 35% were born out of state, 2% were born outside of the United States and 3% were foreign born.