Martinton, IL has a population of 325 and is the 22,047th largest city in the United States. The population density is 1,177 per sq mi which is 429% higher than the Illinois average and 1199% higher than the national average. The median age in Martinton is 37 which is approximately 2% lower than the Illinois average of 37. In Martinton, 59% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 86% of Martinton residents were born in Illinois, 13% were born out of state, 0% were born outside of the United States and 1% were foreign born.