The present invention relates to a display device and a driving method thereof. The driving method of the display device comprises: storing information on a stitch pattern; setting a data processing region disposed in a vicinity of a horizontal center line of a display panel and including a plurality of pixels; and performing data processing of changing gray of data for a portion of the plurality of pixels of the data processing region according to the information on the stitch pattern. The display device comprises: a display panel comprising a plurality of pixels arranged in a matrix, a plurality of first data lines disposed in a first display panel region on a first side of a horizontal center line, and a plurality of second data lines disposed in a second display panel region on a second side of the horizontal center line opposite the first side; a first data driver configured to apply data voltages to the plurality of first data lines; and a second data driver configured to apply data voltages to the plurality of second data lines.