A flexible display device. A plurality of back bars are attached to a rear surface of a display panel and a side cap coupled to the back bars while covering an edge of the display panel. A portion of a front surface of the display is provided adjacent to the edge. The flexible display device prevents edges of the display panel from being damaged, light from leaking through the edges, and the display panel from being scratched or damaged by friction during rolling of the display panel. The edges of an ultrathin display panel are protected from external impacts so that the edges are not damaged, and light leakage on the edges of the display panel is prevented. The display panel is prevented from being scratched or damaged while being rolled.