Mount Auburn, IL has a population of 580 and is the 18,643rd largest city in the United States. The population density is 582 per sq mi which is 162% higher than the Illinois average and 542% higher than the national average. The median age in Mount Auburn is 37 which is approximately 2% lower than the Illinois average of 37. In Mount Auburn, 70% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 93% of Mount Auburn residents were born in Illinois, 6% were born out of state, 0% were born outside of the United States and 1% were foreign born.