Mazon, IL has a population of 957 and is the 15,425th largest city in the United States. The population density is 1,622 per sq mi which is 630% higher than the Illinois average and 1690% higher than the national average. The median age in Mazon is 36 which is approximately 5% lower than the Illinois average of 37. In Mazon, 57% of the population over 15 years of age are married, 95% speak English and 5% speak Spanish. 78% of Mazon residents were born in Illinois, 20% were born out of state, 0% were born outside of the United States and 2% were foreign born.