Palos Hills, IL has a population of 17,545 and is the 2,469th largest city in the United States. The population density is 4,132 per sq mi which is 1759% higher than the Illinois average and 4461% higher than the national average. The median age in Palos Hills is 41 which is approximately 10% higher than the Illinois average of 37. In Palos Hills, 54% of the population over 15 years of age are married, 55% speak English and 7% speak Spanish. 64% of Palos Hills residents were born in Illinois, 6% were born out of state, 1% were born outside of the United States and 29% were foreign born.