According to one embodiment, a liquid crystal display device includes a liquid crystal display panel, a first illumination unit configured to illuminate the liquid crystal display panel with light which is emitted in a first emission direction, a second illumination unit configured to illuminate the liquid crystal display panel with light which is emitted in a second emission direction different from the first emission direction, and a controller configured to control the liquid crystal display panel, the first illumination unit and the second illumination unit in a first display mode in which 3D display with power saving is effected, and in a second display mode in which 3D display with a wider viewing angle than in the first display mode is effected.