Red Bud, IL has a population of 3,597 and is the 7,925th largest city in the United States. The population density is 1,478 per sq mi which is 565% higher than the Illinois average and 1531% higher than the national average. The median age in Red Bud is 40 which is approximately 7% higher than the Illinois average of 37. In Red Bud, 68% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 70% of Red Bud residents were born in Illinois, 28% were born out of state, 0% were born outside of the United States and 2% were foreign born.