A window molding apparatus includes an upper mold, a lower mold under the upper mold, and a side mold under the upper mold and adjacent to at least one side of the lower mold. The upper mold includes a first surface, the lower mold includes a second surface having a portion facing the first surface, and the side mold includes a third surface. The first surface includes a first flat surface and a first bent surface extending from the first flat surface, the second surface includes a second flat surface facing the first flat surface and a second bent surface extending from the second flat surface, and the third surface includes a third bent surface contacting one end of the first bent surface and facing the second bent surface.