An OLED device includes a substrate having a display region including a pixel region and first and second peripheral regions surrounding the pixel region. A bending region is between the display region and the second peripheral region. A buffer layer has a first opening exposing an upper surface of the substrate. A plurality of pixel structures is disposed in the pixel region on the buffer layer. An insulation layer structure is disposed on the buffer layer. The insulation layer structure has a second opening exposing an upper surface of the substrate that is disposed in the bending region and a first portion of the buffer layer that is disposed adjacent to the bending region. A fan-out wiring is disposed between two adjacent insulation layers of the plurality of insulation layers. The fan-out wiring is disposed in the first peripheral region and/or the second peripheral region.