Delavan, IL has a population of 1,600 and is the 12,332nd largest city in the United States. The population density is 1,129 per sq mi which is 408% higher than the Illinois average and 1146% higher than the national average. The median age in Delavan is 41 which is approximately 9% higher than the Illinois average of 37. In Delavan, 70% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 84% of Delavan residents were born in Illinois, 15% were born out of state, 1% were born outside of the United States and 1% were foreign born.