Disclosed are an organic light emitting device and a method of fabricating the same. The method of fabricating an organic light emitting device comprises forming a flexible substrate, and forming an organic light emitting layer on the flexible substrate. The forming the flexible substrate comprises, forming a first polymer pattern on a first metal layer, forming a second metal layer on an exposed portion of the first metal layer through the first polymer pattern, forming a gas barrier layer on the first polymer pattern and the second metal layer, forming a second polymer layer on the gas barrier layer, and removing the first metal layer to expose a surface of the first polymer pattern and a surface of the second metal layer.