Martinsville, IL has a population of 1,261 and is the 13,732nd largest city in the United States. The population density is 614 per sq mi which is 176% higher than the Illinois average and 578% higher than the national average. The median age in Martinsville is 38 which is approximately 2% higher than the Illinois average of 37. In Martinsville, 62% of the population over 15 years of age are married, 98% speak English and 1% speak Spanish. 51% of Martinsville residents were born in Illinois, 49% were born out of state, 0% were born outside of the United States and 0% were foreign born.