A backlight device includes a light guide plate having an incident surface, a first side surface, and a second side surface. The first side surface extends from a first end of the incident surface and the second side surface extends from a second end of the incident surface. A green illuminant faces the incident surface and emits a green light toward the incident surface. A red illuminant faces the incident surface and emits a red light toward the incident surface. A white illuminant disposed on a side of at least one end of the first and second ends of the incident surface emits a white light toward the light guide plate. At least one of the emitted green light and the emitted red light includes a blue component having an emission peak wavelength in a range of 420 to 500 nm.