It is aimed to provide an LCD backlight device and liquid crystal display that can suppress light quantity loss and ensure uniform brightness.An LCD backlight device 101 has a laser light source 1 that emits laser light, and a light guiding plate 3 that transforms the laser light from the laser light source 1 into linear laser light, and transforms the linear laser light into a planar laser light, and emits the planar laser light, and the light guiding plate 3 has a third side face 6 that transforms the linear laser light into the planar laser light by reflecting the linear laser light by a plurality of reflection surfaces that are formed along the entrance direction of the linear laser light.