Mount Morris, IL has a population of 3,008 and is the 8,804th largest city in the United States. The population density is 1,813 per sq mi which is 695% higher than the Illinois average and 1901% higher than the national average. The median age in Mount Morris is 42 which is approximately 12% higher than the Illinois average of 37. In Mount Morris, 58% of the population over 15 years of age are married, 97% speak English and 3% speak Spanish. 82% of Mount Morris residents were born in Illinois, 16% were born out of state, 1% were born outside of the United States and 1% were foreign born.