Clarksville, MI has a population of 375 and is the 21,234th largest city in the United States. The population density is 744 per sq mi which is 638% higher than the Michigan average and 721% higher than the national average. The median age in Clarksville is 34 which is approximately 14% lower than the Michigan average of 40. In Clarksville, 63% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 87% of Clarksville residents were born in Michigan, 12% were born out of state, 1% were born outside of the United States and 1% were foreign born.