Greenville, IL has a population of 6,833 and is the 5,261st largest city in the United States. The population density is 1,090 per sq mi which is 390% higher than the Illinois average and 1103% higher than the national average. The median age in Greenville is 35 which is approximately 6% lower than the Illinois average of 37. In Greenville, 41% of the population over 15 years of age are married, 93% speak English and 4% speak Spanish. 57% of Greenville residents were born in Illinois, 36% were born out of state, 1% were born outside of the United States and 5% were foreign born.