A flexible display device includes a base film, a display panel on the base film, a protective film on a surface of the display panel away from the base film, and an adhesive layer. An area of the protective film is less than that of the display panel. The adhesive layer and the protective film has an overlapping portion. The adhesive layer has a thickness and Young's modulus between 10 and 500 μm and between 0.1 and 10 GPa, respectively. A side edge of the base film, a side edge of the display panel, and a side edge of the adhesive layer are substantially aligned.