There are
781 mi
from Pasadena, TX to Clarksville, TN
That's the driving distance. It would take 14 hours 31 mins to go from Pasadena, Texas to Clarksville, Tennessee.
The flight distance (direct flight from Pasadena, TX to Clarksville, TN) is 654.97 mi.
781 mi = 1,257.30 kms