The invention relates to a door drive device for a door (2) of a wagon (3), comprising at least one door panel mount (12A, 12B) displaceable along a first spatial axis (Y) substantially vertical to the plane of a door panel (20A, 20B) mounted on the at least one door panel mount (12A, 12B) and along a second spatial axis (X) extending substantially horizontal in use and substantially vertical to the first spatial axis (Y), a drive motor (14) and a spindle (15) which may be rotated by means of the drive motor (14). It is provided, that a displacement of the at least one door panel mount (12A, 12B) along the first and/or second spatial axis (Y, X) is effected by means of a guide fork (13A, 13B) being displaceable by an associated spindle nut (16A, 16B) slidably engaged with the guide fork (13A, 13B), wherein the spindle nut (16A, 16B) is driven by rotation of a spindle (15) and wherein the spindle (15) and the drive motor (14) are fixed with respect to the wagon (3).