An organic light emitting display, OLED, device, comprising: a substrate having an opening region, a peripheral region surrounding the opening region, a display region surrounding the peripheral region, and a pad region located at a side of the display region, the substrate including a first groove formed in the peripheral region and an opening formed in the opening region, wherein the first groove has a lower portion which is larger than its upper portion; pad electrodes in the pad region on the substrate; a light emitting structure in the display region on the substrate; a first conductive pattern overlapping the first groove in the peripheral region on the substrate, the first conductive pattern being electrically connected to the pad electrodes through a connection wiring, which is disposed in an outer portion of the display region and the pad region; and a functional module in the opening, wherein the substrate includes: a first organic film layer; a first barrier layer on the first organic film layer; a second organic film layer on the first barrier layer, the second organic film layer having a trench in the peripheral region; and a second barrier layer on the second organic film layer, the second barrier layer being located on the trench and having a protruding portion that protrudes in an inner portion of the trench, the second barrier layer having an opening defined by the protruding portion, and wherein the first conductive pattern overlaps the protruding portion of the second barrier layer. a substrate having an opening region, a peripheral region surrounding the opening region, a display region surrounding the peripheral region, and a pad region located at a side of the display region, the substrate including a first groove formed in the peripheral region and an opening formed in the opening region, wherein the first groove has a lower portion which is larger than its upper portion; pad electrodes in the pad region on the substrate; a light emitting structure in the display region on the substrate; a first conductive pattern overlapping the first groove in the peripheral region on the substrate, the first conductive pattern being electrically connected to the pad electrodes through a connection wiring, which is disposed in an outer portion of the display region and the pad region; and a functional module in the opening, wherein the substrate includes: a first organic film layer; a first barrier layer on the first organic film layer; a second organic film layer on the first barrier layer, the second organic film layer having a trench in the peripheral region; and a second barrier layer on the second organic film layer, the second barrier layer being located on the trench and having a protruding portion that protrudes in an inner portion of the trench, the second barrier layer having an opening defined by the protruding portion, and wherein the first conductive pattern overlaps the protruding portion of the second barrier layer. a first organic film layer; a first barrier layer on the first organic film layer; a second organic film layer on the first barrier layer, the second organic film layer having a trench in the peripheral region; and a second barrier layer on the second organic film layer, the second barrier layer being located on the trench and having a protruding portion that protrudes in an inner portion of the trench, the second barrier layer having an opening defined by the protruding portion, and wherein the first conductive pattern overlaps the protruding portion of the second barrier layer.