OLED display that includes: a substrate; a plurality of thin film transistors formed on the substrate; a plurality of first electrodes respectively connected to the thin film transistors; a pixel definition layer formed on the substrate and having a first opening, a second opening, and a third opening respectively exposing first, second, and third first electrodes of the plurality of first electrodes; an emission layer formed at the first opening, the second opening, and the third opening; and a second electrode formed on the emission layer, wherein the first opening has a first pair of boundary lines facing each other and a second pair of boundary lines facing each other, and the first pair of boundary lines overlap boundary lines of a pair of boundary lines of the first first electrode or are positioned outside the boundary lines of the pair of boundary lines of the first first electrode.