Hainesville, IL has a population of 3,671 and is the 7,826th largest city in the United States. The population density is 1,989 per sq mi which is 795% higher than the Illinois average and 2095% higher than the national average. The median age in Hainesville is 32 which is approximately 14% lower than the Illinois average of 37. In Hainesville, 59% of the population over 15 years of age are married, 73% speak English and 15% speak Spanish. 63% of Hainesville residents were born in Illinois, 20% were born out of state, 1% were born outside of the United States and 15% were foreign born.