According to one embodiment, a liquid crystal display device includes a first substrate including a transmissive pixel electrode disposed in a transmissive display area, and a reflective pixel electrode with a planar plate shape which is disposed in a reflective display area, a second substrate including a common electrode, a liquid crystal layer being configured to have a less thickness in the reflective display area than in the transmissive display area, to impart a phase difference of ¼ wavelength to light passing at an OFF time in the reflective display area, and to impart no phase difference to light passing at an ON time in the reflective display area, and a retardation plate disposed between a second polarizer and the second substrate in the reflective display area.