Champaign, IL has a population of 84,672 and is the 399th largest city in the United States. The population density is 3,712 per sq mi which is 1570% higher than the Illinois average and 3997% higher than the national average. The median age in Champaign is 28 which is approximately 26% lower than the Illinois average of 37. In Champaign, 39% of the population over 15 years of age are married, 80% speak English and 5% speak Spanish. 63% of Champaign residents were born in Illinois, 22% were born out of state, 1% were born outside of the United States and 14% were foreign born.