A display device includes a first member, a second member, image signal lines, signal sources, synchronization line terminals, and synchronization lines. The first member includes a display area. The second member includes a plate surface greater than the plate surface of the first member and a display area. The second member includes a covered portion covered with the first member and an uncovered portion not covered with the first member. The image signal lines are disposed in the covered portion. The signal sources are mounted to signal source mounting areas of the uncovered portion. The synchronization line terminals are disposed in the signal source mounting areas and coupled to the signal sources. The synchronization lines are disposed in the covered portion and the uncovered portion and coupled to the synchronization line terminals. Some of the synchronization lines cross a border between the covered portion and the uncovered portion.