Cornell, IL has a population of 358 and is the 21,473rd largest city in the United States. The population density is 558 per sq mi which is 151% higher than the Illinois average and 516% higher than the national average. The median age in Cornell is 40 which is approximately 8% higher than the Illinois average of 37. In Cornell, 52% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 92% of Cornell residents were born in Illinois, 8% were born out of state, 0% were born outside of the United States and 1% were foreign born.