Green Valley, IL has a population of 689 and is the 17,583rd largest city in the United States. The population density is 2,270 per sq mi which is 921% higher than the Illinois average and 2405% higher than the national average. The median age in Green Valley is 40 which is approximately 7% higher than the Illinois average of 37. In Green Valley, 69% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 85% of Green Valley residents were born in Illinois, 13% were born out of state, 1% were born outside of the United States and 0% were foreign born.