Clinton, IL has a population of 7,195 and is the 5,084th largest city in the United States. The population density is 1,983 per sq mi which is 792% higher than the Illinois average and 2088% higher than the national average. The median age in Clinton is 40 which is approximately 6% higher than the Illinois average of 37. In Clinton, 56% of the population over 15 years of age are married, 96% speak English and 4% speak Spanish. 83% of Clinton residents were born in Illinois, 14% were born out of state, 1% were born outside of the United States and 2% were foreign born.