An organic light-emitting device includes a substrate, a bottom electrode on the substrate, an organic light-emitting layer on the bottom electrode, and a top electrode on the organic light-emitting layer, wherein the top electrode includes a first electrode part, a grid-shaped or plate-shaped second electrode part on the first electrode part, and an adhesive layer on the second electrode part. The organic light-emitting device includes the top electrode that has low sheet resistance. The top electrode includes a graphene layer as the first electrode part.