A display device includes a display panel including an edge extending along a first direction, a main circuit board adjacent to the edge of the display panel, and a connection circuit board which connects the main circuit board to the display panel at the edge thereof. The connection circuit board includes a plurality of board side pads which are arranged along the first direction and at which the connection circuit board is connected to the main circuit board. Each of the plurality of board side pads includes a first pad, and a second pad adjacent to the first pad along the first direction. The second pad includes a plurality of signal pads which are arranged along a second direction which crosses the first direction and are each aligned with the first pad along the first direction.