A display device includes a display panel, and a first flexible printed circuit board bonded to a side surface of the display panel. The display panel includes: a first substrate; a first extension wire on a top surface of the first substrate, the top surface being parallel to a first direction and a second direction, the second direction being perpendicular to the first direction; a first recess portion at a side surface of the first substrate; and a first pad that extends from the first extension wire in a third direction perpendicular to the first and second directions, the first pad being disposed in the recess portion, and the first extension wire and the first pad comprise the same material.