There are
365 mi
from Decatur, IL to Leavenworth, KS
That's the driving distance. It would take 6 hours 59 mins to go from Decatur, Illinois to Leavenworth, Kansas.
The flight distance (direct flight from Decatur, IL to Leavenworth, KS) is 319.85 mi.
365 mi = 586.65 kms