A foldable display device includes a display panel including a first display area and a second display area, a timing controller configured to receive input image data and to provide a first data packet corresponding to the first display area and a second data packet corresponding to the second display area concurrently, and a data driver configured to receive the first data packet and the second data packet, to determine whether the first display area or the second display area is folded based on the first data packet and the second data packet, and to not output a first data signal corresponding to the first data packet or a second data signal corresponding to the second data packet when the first display area or the second display area is folded.