A vehicle display device includes an HUD device that projects a display image onto a front windshield arranged in front of a driver's seat of a vehicle, and overlaps the display image with scenery in front of the vehicle to display the display image as a virtual image, and a front photographing camera that is installed in the vehicle and photographs at least the scenery in front of the vehicle. The HUD device adjusts contrast of the display image with respect to the scenery in front of the vehicle based on an image of an extracted image region including a portion overlapping with at least part of the display image when viewed from an eye point in a scenery photographing image photographed by the front photographing camera, the eye point corresponding to a position of an eye of a driver on the driver's seat.