Wellington, IL has a population of 283 and is the 22,799th largest city in the United States. The population density is 1,030 per sq mi which is 364% higher than the Illinois average and 1037% higher than the national average. The median age in Wellington is 40 which is approximately 6% higher than the Illinois average of 37. In Wellington, 65% of the population over 15 years of age are married, 91% speak English and 5% speak Spanish. 84% of Wellington residents were born in Illinois, 13% were born out of state, 0% were born outside of the United States and 4% were foreign born.