Phoenix, IL has a population of 2,042 and is the 10,896th largest city in the United States. The population density is 4,404 per sq mi which is 1881% higher than the Illinois average and 4761% higher than the national average. The median age in Phoenix is 37 which is approximately 2% lower than the Illinois average of 37. In Phoenix, 42% of the population over 15 years of age are married, 89% speak English and 10% speak Spanish. 76% of Phoenix residents were born in Illinois, 20% were born out of state, 0% were born outside of the United States and 4% were foreign born.