what county is clarksville ar in
Sponsored Topics. Clarksville is a city in Johnson County, Arkansas, United States. The population was 7,719 at the 2000 census. The city is the county seat of Johnson County. Clarksville is located at 35Â°27â²50â³N 93Â°28â²38â³W / 35.46389Â°N 93.47722Â°W / 35.46389; -93.47722 (35.464006, -93.477089).