Elgin, IL has a population of 111,919 and is the 255th largest city in the United States. The population density is 2,979 per sq mi which is 1240% higher than the Illinois average and 3188% higher than the national average. The median age in Elgin is 34 which is approximately 10% lower than the Illinois average of 37. In Elgin, 55% of the population over 15 years of age are married, 54% speak English and 39% speak Spanish. 59% of Elgin residents were born in Illinois, 12% were born out of state, 2% were born outside of the United States and 27% were foreign born.