A display device includes a substrate; a buffer layer disposed on the substrate; a first thin-film transistor comprising a first active layer made of a low-temperature poly-silicon (LTPS), a first gate electrode overlapping with the first active layer with the first gate insulating layer and the second gate insulating layer therebetween, and a first source electrode and a first drain electrode electrically connected to the first active layer; and a second thin-film transistor comprising a second active layer made of an oxide semiconductor, a second gate electrode overlapping with the second active layer with the second gate insulating layer therebetween, and a second source electrode and a second drain electrode electrically connected to the second active layer. The first gate electrode of the first thin-film transistor and the second gate electrode of the second thin-film transistor may be disposed on the second gate insulating layer.