An increase in fabricating cost of a display module including a touch sensor is suppressed. A display device which includes a first substrate, a second substrate, and liquid crystal interposed between the first substrate and the second substrate includes a display portion. The display portion includes a sensor unit and a pixel. The sensor unit includes a first transistor, a first conductive film electrically connected to a gate of the first transistor, and a second conductive film. At least part of the first conductive film overlaps with at least part of the second conductive film. The pixel includes a second transistor, and a pixel electrode electrically connected to the second transistor. At least part of the pixel electrode overlaps with at least part of the first conductive film.