A backlight device includes LEDs, a light guide plate, an LED board, and a light blocking portion. The light guide plate includes a side surface configured as a light entrance surface through which light from the LEDs enters and a plate surface configured as a light exit surface through which light exits the light guide plate. The LED board on which the LEDs are mounted and at least a portion of which is a light guide plate overlapping portion is on a light exit surface side. The light guide plate overlapping portion overlaps a light entering edge portion that is an edge portion of the light guide plate close to the light entrance surface. The light blocking portion is at the light guide plate overlapping portion of the LED board and between the light guide plate overlapping portion and the light entering edge portion of the light guide plate.
