Warrenville, IL has a population of 13,415 and is the 3,118th largest city in the United States. The population density is 2,469 per sq mi which is 1011% higher than the Illinois average and 2625% higher than the national average. The median age in Warrenville is 37 which is approximately 1% lower than the Illinois average of 37. In Warrenville, 58% of the population over 15 years of age are married, 75% speak English and 17% speak Spanish. 65% of Warrenville residents were born in Illinois, 18% were born out of state, 1% were born outside of the United States and 16% were foreign born.