Lisle, IL has a population of 22,989 and is the 1,895th largest city in the United States. The population density is 3,267 per sq mi which is 1369% higher than the Illinois average and 3506% higher than the national average. The median age in Lisle is 37 which is approximately equal to the Illinois average of 37. In Lisle, 55% of the population over 15 years of age are married, 81% speak English and 5% speak Spanish. 63% of Lisle residents were born in Illinois, 21% were born out of state, 1% were born outside of the United States and 15% were foreign born.