A windrow door assembly for controlling a direction of flow of crop residue expelled from a combine is disclosed. The window door assembly may generally include a door panel extending between a first end and a second end. The door panel may be moveable between a closed position, wherein the crop residue being expelled from the combine is directed along the door panel into a spreader of the combine, and an opened position, wherein the crop residue is directed along the door panel towards a rear opening of the combine. In addition, the windrow door assembly may include a deflector panel rotatably coupled to the door panel. The deflector panel may be configured to alter the direction of flow of the crop residue when the door panel is in the opened position.