The present technology relates to a display device and a signal processing device that have made it possible to actively utilize maximumly a color gamut that a display panel can express.
Provided is a display device, including: a display section in which display pixels that each include a first subpixel, a second subpixel, and a third subpixel that emit three-basic-color light and a fourth subpixel that emits non-basic-color light are arranged two-dimensionally; a first signal processing section that expands a video signal being input and corresponding to the basic-color light and adapts the video signal to a color gamut that the display section can express; and a second signal processing section that converts an expanded video signal being the video signal having been expanded into a first signal, a second signal, and a third signal that correspond to the basic-color light and a fourth signal that corresponds to the non-basic-color light, and outputs the signals to the display section. The present technology can be applied to, for example, a self-light-emission type display device, such as an organic EL display device.