Provided are a display device, a mask assembly, and an apparatus and a method for manufacturing the display device. The mask assembly includes: a mask frame; at least two mask sheets installed on the mask frame, each of the mask sheets including a plurality of openings; and at least two thin shielding plates installed on the mask frame such that the thin shielding plates are spaced apart from each other and shield a portion of the plurality of openings of each mask sheet, wherein one of the mask sheets and the thin shielding plates includes a shielding portion between the thin shielding plates spaced apart from each other, the shielding portion selectively blocking at least portions of the openings so as to form a deposition region having a shape other than a rectangle or a square.