An image rendering apparatus and method for rendering a stereoscopic image are provided. The image rendering apparatus may estimate a disparity of an image pixel included in an input image. Based on the disparity, a viewpoint direction of the image pixel may be determined by the image rendering apparatus. The image rendering apparatus may render a stereoscopic image by assigning a pixel value of the image pixel to a display pixel having a viewpoint direction corresponding to the viewpoint direction of the image pixel, instead of generating a multiview image.