Provided are: a backlight unit that is capable of increasing the degree of freedom in design of a device on which the backlight unit is mounted; and a display device which is provided with this backlight unit. This backlight unit is provided with: a light source which emits light that illuminates a liquid crystal display element; a light collection means for focusing the light emitted from the light source on a display region (A) of the liquid crystal display element; and a reflective part which has a reflective surface that reflects the light emitted from the light source toward the liquid crystal display element. This backlight unit is configured such that the optical path for the light from the light source to the liquid crystal display element is replicated at the reflective part by having the reflective surface inclined to the optical axis (AX) of the light source.