Clarksville, TN has a population of 146,281 and is the 181st largest city in the United States. The population density is 1,493 per sq mi which is 875% higher than the Tennessee average and 1547% higher than the national average. The median age in Clarksville is 29 which is approximately 25% lower than the Tennessee average of 39. In Clarksville, 56% of the population over 15 years of age are married, 89% speak English and 6% speak Spanish. 34% of Clarksville residents were born in Tennessee, 56% were born out of state, 4% were born outside of the United States and 6% were foreign born.