A flexible display device including a well structure. An organic light-emitting element including a pixel electrode, an organic light-emitting layer, and a common electrode is disposed on a substrate. A bank layer is disposed on the pixel electrode, and is disposed to open at least a part of the pixel electrode. Further, at least one well structure is disposed on the bank layer. The well structure disposed on the bank layer can reduce or minimize a delamination phenomenon of an encapsulation layer which can occur due to compressive and tensile stress caused by bending of the flexible display device.