Winchester, IL has a population of 1,636 and is the 12,199th largest city in the United States. The population density is 1,450 per sq mi which is 552% higher than the Illinois average and 1500% higher than the national average. The median age in Winchester is 38 which is approximately 2% higher than the Illinois average of 37. In Winchester, 57% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 90% of Winchester residents were born in Illinois, 9% were born out of state, 1% were born outside of the United States and 0% were foreign born.