In an organic light emitting diode (OLED) display and a manufacturing method, an organic light emitting diode (OLED) display includes: a substrate; a semiconductor layer pattern formed on the substrate and including a first capacitor electrode; a gate insulating layer covering the semiconductor layer pattern; a first conductive layer pattern formed on the gate insulating layer and including a second capacitor electrode having at least a portion overlapping the first capacitor electrode; an interlayer insulating layer having a capacitor opening exposing a portion of the second capacitor electrode and covering the second capacitor electrode; and a second conductive layer pattern formed on the interlayer insulating layer, wherein the capacitor opening includes a first transverse side wall parallel to and overlapping the second capacitor electrode, a second transverse side wall parallel to and not overlapping the second capacitor electrode, and a longitudinal side wall connecting the first transverse side wall and the second transverse side wall to each other and overlapping the first capacitor electrode.