A flexible display is disclosed. In one aspect, the flexible display includes a flexible display panel including: a first flat portion, a bending portion connected to the first flat portion, and a second flat portion connected to the bending portion and opposing the first flat portion. The flexible display also includes a guide member fixed to the flexible display panel and arranged between the first and second flat portions and a housing supporting the flexible display panel and the guide member and arranged between the first and second flat portions. The flexible display further comprises a sliding member connected to the housing and the guide member and configured to move the second flat portion by substantially the same distance as and in an opposite direction to the first flat portion when the first flat portion is moved.