A foldable display device includes a display panel, a mid-frame arranged on a rear surface of the display panel, including a folding region and unfolding regions formed at both sides of the folding region, and configured to have a perforated pattern formed in the folding region, a first adhesive layer and a second adhesive layer arranged in the respective unfolding regions on a rear surface of the mid-frame, and an insert arranged corresponding to the folding region on the rear surface of the mid-frame.