Jerome, IL has a population of 1,662 and is the 12,105th largest city in the United States. The population density is 3,607 per sq mi which is 1523% higher than the Illinois average and 3881% higher than the national average. The median age in Jerome is 49 which is approximately 30% higher than the Illinois average of 37. In Jerome, 51% of the population over 15 years of age are married, 92% speak English and 0% speak Spanish. 73% of Jerome residents were born in Illinois, 19% were born out of state, 0% were born outside of the United States and 7% were foreign born.