A light guide plate receives light and guides the light to a display panel. The light guide plate includes a body and protruding portions. The body includes a first side surface disposed adjacent to the light source, a second side surface facing the first side surface, and an upper surface. Protruding portions are protruded from the upper surface. Each of the protruding portions includes first and second protruding portions sequentially arranged from the first side surface to the second side surface. A width of the first protruding portion in a direction substantially parallel to the first side surface becomes smaller as a distance from the first side surface becomes larger, and a width of the second protruding portion in the direction substantially parallel to the first side surface becomes larger as the distance from the first side surface becomes larger.