Carterville, IL has a population of 5,742 and is the 5,920th largest city in the United States. The population density is 1,087 per sq mi which is 389% higher than the Illinois average and 1100% higher than the national average. The median age in Carterville is 34 which is approximately 10% lower than the Illinois average of 37. In Carterville, 58% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 71% of Carterville residents were born in Illinois, 25% were born out of state, 1% were born outside of the United States and 3% were foreign born.