Mendota, IL has a population of 7,182 and is the 5,090th largest city in the United States. The population density is 1,420 per sq mi which is 539% higher than the Illinois average and 1468% higher than the national average. The median age in Mendota is 39 which is approximately 3% higher than the Illinois average of 37. In Mendota, 56% of the population over 15 years of age are married, 78% speak English and 20% speak Spanish. 78% of Mendota residents were born in Illinois, 14% were born out of state, 0% were born outside of the United States and 8% were foreign born.