A foldable display device includes a display panel; a first support member and a second support member disposed on a surface of the display panel and respectively including first biasing members; a first member and a second member that are respectively slideably coupled to the first support member and the second support member and respectively include second biasing members; and a hinge member connected to the first member and the second member to vary an angle between the first member and the second member with respect to at least one rotation axis.