To provide a cooling device with improved cooling efficiency and a display device capable of preventing brightness variations.

There are provided a display panel 10 and the cooling device 20 having a cooling medium to be circulated between a cooling portion 210 and a heat radiation portion 220. Into the cooling portion 210, the cooling medium is filled at its upper part and discharged at its lower part. Into the heat radiation portion 220, the cooling medium is filled at its upper part and discharged at its lower part. The display panel 10 has a temperature higher at its upper part with the convection of ambient air, but temperature rise in the display panel 10 at its upper part is suppressed by filling the cooling medium into the cooling portion 210 at its upper part. Thereby, there are a lower average temperature in the display panel 10 and a small difference in temperature, preventing the occurrence of brightness variations or adverse effects of heat such as shorter life.