A foldable display device can include a display panel including a first non-folding part, a second non-folding part and a folding part disposed between the first and second non-folding parts; a support disposed on a rear surface of the display panel; and a back cover disposed on a rear surface of the support, in which the back cover includes open patterns exposing the support, and folding patterns disposed on an area of the rear surface of the support corresponding to the folding part, the support includes protruding patterns disposed on an area of the support corresponding to the open patterns of the back cover, and the protruding patterns are fitted into the open patterns.