Granite City, IL has a population of 29,662 and is the 1,446th largest city in the United States. The population density is 1,533 per sq mi which is 589% higher than the Illinois average and 1592% higher than the national average. The median age in Granite City is 41 which is approximately 10% higher than the Illinois average of 37. In Granite City, 54% of the population over 15 years of age are married, 95% speak English and 3% speak Spanish. 69% of Granite City residents were born in Illinois, 28% were born out of state, 1% were born outside of the United States and 3% were foreign born.