Sheridan, IL has a population of 2,543 and is the 9,753rd largest city in the United States. The population density is 1,275 per sq mi which is 474% higher than the Illinois average and 1308% higher than the national average. The median age in Sheridan is 31 which is approximately 16% lower than the Illinois average of 37. In Sheridan, 22% of the population over 15 years of age are married, 93% speak English and 6% speak Spanish. 82% of Sheridan residents were born in Illinois, 16% were born out of state, 2% were born outside of the United States and 1% were foreign born.