Dallas City, IL has a population of 1,233 and is the 13,874th largest city in the United States. The population density is 519 per sq mi which is 128% higher than the Illinois average and 473% higher than the national average. The median age in Dallas City is 46 which is approximately 22% higher than the Illinois average of 37. In Dallas City, 55% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 43% of Dallas City residents were born in Illinois, 56% were born out of state, 0% were born outside of the United States and 1% were foreign born.