Peoria Heights, IL has a population of 6,056 and is the 5,672nd largest city in the United States. The population density is 2,400 per sq mi which is 939% higher than the Illinois average and 2549% higher than the national average. The median age in Peoria Heights is 38 which is approximately 3% higher than the Illinois average of 37. In Peoria Heights, 45% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 79% of Peoria Heights residents were born in Illinois, 18% were born out of state, 1% were born outside of the United States and 2% were foreign born.