Fithian, IL has a population of 468 and is the 19,935th largest city in the United States. The population density is 1,223 per sq mi which is 450% higher than the Illinois average and 1250% higher than the national average. The median age in Fithian is 51 which is approximately 37% higher than the Illinois average of 37. In Fithian, 62% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 89% of Fithian residents were born in Illinois, 11% were born out of state, 0% were born outside of the United States and 1% were foreign born.