Bartlett, IL has a population of 41,475 and is the 989th largest city in the United States. The population density is 2,646 per sq mi which is 1061% higher than the Illinois average and 2821% higher than the national average. The median age in Bartlett is 39 which is approximately 4% higher than the Illinois average of 37. In Bartlett, 69% of the population over 15 years of age are married, 72% speak English and 6% speak Spanish. 68% of Bartlett residents were born in Illinois, 12% were born out of state, 1% were born outside of the United States and 19% were foreign born.