An optical film includes a polarizing film including a polyolefin and a dichroic dye, a first photo-alignment layer on a side of the polarizing film, and a first liquid crystal layer on a side of the first photo-alignment layer, wherein the polarizing film and the first liquid crystal layer are in close contact with the first photo-alignment layer to provide a self-integrated structure. A method of manufacturing the same and a display device including the optical film are also provided.