The invention discloses a flexible display device which includes a substrate, a plurality of first pixels, and a plurality of second pixels. The substrate includes a foldable bending region and a non-foldable non-bending region. Each first pixel is disposed on the bending region. Each first pixel is spaced apart from an adjacent first pixel by a first distance. Each second pixel is disposed on thenon-bending region. Each second pixel is spaced apart from an adjacent second pixel by a second distance. The first distance is greater than the second distance.