Tampico, IL has a population of 621 and is the 18,216th largest city in the United States. The population density is 1,602 per sq mi which is 621% higher than the Illinois average and 1668% higher than the national average. The median age in Tampico is 45 which is approximately 21% higher than the Illinois average of 37. In Tampico, 63% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 84% of Tampico residents were born in Illinois, 14% were born out of state, 0% were born outside of the United States and 2% were foreign born.