Middletown, MO has a population of 233 and is the 23,756th largest city in the United States. The population density is 725 per sq mi which is 739% higher than the Missouri average and 700% higher than the national average. The median age in Middletown is 32 which is approximately 16% lower than the Missouri average of 38. In Middletown, 51% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 85% of Middletown residents were born in Missouri, 15% were born out of state, 0% were born outside of the United States and 0% were foreign born.