Pierron, IL has a population of 391 and is the 20,989th largest city in the United States. The population density is 468 per sq mi which is 110% higher than the Illinois average and 416% higher than the national average. The median age in Pierron is 47 which is approximately 26% higher than the Illinois average of 37. In Pierron, 59% of the population over 15 years of age are married, 97% speak English and 3% speak Spanish. 73% of Pierron residents were born in Illinois, 24% were born out of state, 1% were born outside of the United States and 3% were foreign born.