Antioch, IL has a population of 14,342 and is the 2,932nd largest city in the United States. The population density is 1,776 per sq mi which is 699% higher than the Illinois average and 1860% higher than the national average. The median age in Antioch is 37 which is approximately 1% lower than the Illinois average of 37. In Antioch, 62% of the population over 15 years of age are married, 91% speak English and 3% speak Spanish. 74% of Antioch residents were born in Illinois, 18% were born out of state, 1% were born outside of the United States and 7% were foreign born.