Provided is a vehicle display device that emits light whereby, e.g., other vehicles, etc., can be easily visible from outside the vehicle. A door mirror 2 applying this vehicle display device comprises a light-emission device 3 having a light source 30 and a light-guide plate 31. The light-guide plate 31 has: a light-emission surface 33 that emits incident light; and a light path-changing unit 35that changes the light path of the incident light to the light-emission surface 33 side. The light path-changing unit 35 is arranged so as to emit light in a prescribed direction, e.g., towards outside the vehicle. As a result, light can be emitted such that the entire mirror surface of the door mirror 2 is visible from a prescribed direction only.