There are
548 mi
from Decatur, IL to South Sioux City, NE
That's the driving distance. It would take 10 hours 6 mins to go from Decatur, Illinois to South Sioux City, Nebraska.
The flight distance (direct flight from Decatur, IL to South Sioux City, NE) is 428.07 mi.
548 mi = 881.37 kms