An over-the-door organizer includes a first mounting rack, a plurality of second mounting racks, a plurality of storage baskets, and a plurality of hanging plates. The plurality of hanging plates are connected to the first mounting rack, and the first mounting rack is hung on a door through the plurality of hanging plates. The plurality of second mounting racks are detachably connected one by one to form a whole and then detachably connected to the first mounting rack. Each of the first mounting rack and the second mounting racks is provided with a plurality of pairs of mounting holes at an interval. Each of the storage baskets is provided with a pair of hooks, and the pair of hooks are detachably connected to any pair of mounting holes. The storage baskets are hung by inserting the hooks into the mounting holes at different positions, and the spacing between each two adjacent storage baskets is adjustable.