A display device includes a first substrate and a second substrate, and the first substrate includes a plurality of connection lines disposed to extend to an end of the first substrate and a plurality of pads disposed on a side surface of the first substrate and electrically connected to the plurality of connection lines, respectively. Each of the plurality of connection lines includes a first area and a second area extending from the first area, the first area has a width greater than a width of the second area, and the width of the second area is substantially the same as a width of each of the plurality of pads.