An apparatus and method for driving an image display device is disclosed, in which data signals are transmitted in a multilevel to reduce transmission frequencies, power consumption and transmission lines. The apparatus for driving an image display device includes a display panel including an image display unit for displaying images, a plurality of data driver integrated circuits supplying image signals to the image display unit, and a timing controller converting externally supplied i bit digital source data (i is a positive number) to a plurality of voltage levels to supply the converted voltage levels to the respective data driver integrated circuits and controlling the data driver integrated circuits.