The present invention provides a mirror display that can match the peripheral environment having diffusely reflecting surfaces in the mirror mode, and an electronic device including the mirror display. The mirror display includes a half mirror plate that includes a reflective polarizer and a display device. The half mirror plate further includes a light-diffusing member that diffuses at least part of incident light. The mirror display includes, in the order from the back surface side, the display device, the reflective polarizer, and the light-diffusing member.