There are
1,115 mi
from Harlingen, TX to Ballwin, MO
That's the driving distance. It would take 20 hours 51 mins to go from Harlingen, Texas to Ballwin, Missouri.
The flight distance (direct flight from Harlingen, TX to Ballwin, MO) is 952.37 mi.
1,115 mi = 1,794.93 kms