An organic light-emitting display device includes a substrate; a thin-film transistor on the substrate; a first insulating layer covering the thin-film transistor; a first electrode on the first insulating layer, and electrically connected to the thin-film transistor; a second insulating layer on the first insulating layer so as to cover the first electrode, and having an opening for exposing a part of the first electrode; a porous member in the second insulating layer; a second electrode on the second insulating layer, and facing the first electrode so as to correspond to the opening; and an organic emission layer between the first electrode and the second electrode so as to correspond to the opening. The organic light-emitting display device may prevent degradation of characteristics of an organic light-emitting device due to discharge of gas from an organic material.