The present disclosure provides a backplate including a first plate coupled to the rear surface of a flexible display panel, a second plate disposed opposite the first plate while being spaced apart therefrom, and an elastic part disposed between the first plate and the second plate and configured to resiliently change a distance between the first plate and the second plate. The present disclosure further provides a rollable display device including a flexible display panel, a backplate coupled to the rear surface of the flexible display panel, and a case accommodating a roller configured to roll or unroll the flexible display panel and the backplate together and having therein an entrance through which the flexible display panel and the backplate are introduced into or drawn out of the case. When the flexible display panel and the backplate are rolled around the roller, the backplate is gradually reduced in thickness.