Martinsburg, OH has a population of 248 and is the 23,464th largest city in the United States. The population density is 1,404 per sq mi which is 388% higher than the Ohio average and 1450% higher than the national average. The median age in Martinsburg is 29 which is approximately 26% lower than the Ohio average of 39. In Martinsburg, 43% of the population over 15 years of age are married, 100% speak English and 0% speak Spanish. 83% of Martinsburg residents were born in Ohio, 17% were born out of state, 0% were born outside of the United States and 0% were foreign born.