A display device includes a display panel, a light guide plate, a light source unit, a wavelength conversion sheet which is disposed between the display panel and the light guide plate, and a bottom chassis where the wavelength conversion sheet includes a first portion which covers an upper surface of the light guide plate, the first portion including a first edge extending in a first direction and a second edge facing the first edge, a second portion which extends from the first edge toward the bottom chassis, is coupled to the bottom chassis and covers a first side surface of the light guide plate, and a third portion which extends from the second edge toward the bottom chassis, is coupled to the bottom chassis and covers a second side surface of the light guide plate.