A display device includes: a display panel including a plurality of pixels, which displays an image; a first circuit board connected to the display panel and which provides a first signal to the display panel; a second circuit board, which provides a second signal to the first circuit board, and a connection board, which electrically connects the first circuit board to the second circuit board and includes a connection portion connected to the first circuit board and the second circuit board. The second circuit board includes a connection detection circuit, which detects a connection status of the connection portion and generates a detection signal.