Peoria Heights, IL has a population of 6,019 and is the 5,752nd largest city in the United States. The population density is 2,397 per sq mi which is 978% higher than the Illinois average and 2545% higher than the national average. The median age in Peoria Heights is 36 which is approximately 3% lower than the Illinois average of 37. In Peoria Heights, 51% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 83% of Peoria Heights residents were born in Illinois, 15% were born out of state, 0% were born outside of the United States and 1% were foreign born.