Davis, IL has a population of 688 and is the 17,588th largest city in the United States. The population density is 1,605 per sq mi which is 622% higher than the Illinois average and 1672% higher than the national average. The median age in Davis is 33 which is approximately 12% lower than the Illinois average of 37. In Davis, 68% of the population over 15 years of age are married, 96% speak English and 1% speak Spanish. 73% of Davis residents were born in Illinois, 25% were born out of state, 0% were born outside of the United States and 2% were foreign born.