A flexible display device includes a flexible substrate, an inorganic barrier layer, a metal layer, an organic buffer layer, and an insulating layer. The inorganic barrier layer is located on the flexible substrate. The metal layer is located on the inorganic barrier layer and in contact with the inorganic barrier layer. The organic buffer layer covers the inorganic barrier layer and the metal layer, and has at least one conductive via connected to the metal layer. The insulating layer is located on the organic buffer layer.