There are
669 mi
from Clarksville, TN to Gainesville, TX
That's the driving distance. It would take 12 hours 22 mins to go from Clarksville, Tennessee to Gainesville, Texas.
The flight distance (direct flight from Clarksville, TN to Gainesville, TX) is 587.60 mi.
669 mi = 1,076.79 kms