Bellflower, IL has a population of 416 and is the 20,648th largest city in the United States. The population density is 1,134 per sq mi which is 410% higher than the Illinois average and 1152% higher than the national average. The median age in Bellflower is 35 which is approximately 6% lower than the Illinois average of 37. In Bellflower, 63% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 84% of Bellflower residents were born in Illinois, 15% were born out of state, 0% were born outside of the United States and 0% were foreign born.