Salem, MO has a population of 4,974 and is the 6,509th largest city in the United States. The population density is 1,567 per sq mi which is 1714% higher than the Missouri average and 1629% higher than the national average. The median age in Salem is 42 which is approximately 9% higher than the Missouri average of 38. In Salem, 52% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 77% of Salem residents were born in Missouri, 22% were born out of state, 0% were born outside of the United States and 1% were foreign born.