A signal processing device and an image display apparatus including the same are disclosed. A signal processing device and an image display apparatus including the same according to an embodiment of the present disclosure includes: an afterimage analyzer to calculate image accumulation information based on an input image, an afterimage learning processor to perform learning based on the image accumulation information and adjust an afterimage reducing strength based on the learning, and an afterimage reducing processor to perform an afterimage reducing process based on the afterimage reducing strength from the afterimage learning processor. Accordingly, an afterimage of the image display apparatus including the organic light emitting diode panel may be reduced.