A flexible display device includes a flexible display panel and a first outer member having a groove pattern. The first groove pattern includes: a first inclined portion having a first surface inclined to the surface of the display panel at an obtuse angle relative to the surface of the display panel; and a second inclined portion spaced apart from the first inclined portion in a second direction crossing the first direction, the second inclined portion having a second surface inclined to the surface of the display panel at an obtuse angle relative to the surface of the display panel.