There is provided is a display device capable of suppressing deterioration of the color conversion layer which converts one color light into another color light, and realizing favorable handling and a display device using the color conversion layer, and a color conversion sheet. A phosphor sheet 10 is, for example, arranged immediately above a light source such as a blue light emitting diode, and obtained by sealing a phosphor layer 11, which converts a part of blue light into another color light, by sealing sheets 12A and 12B. The sealing sheets 12A and 12B are bonded with the phosphor layer 11 in between by a first bonding layer 13 and a second bonding layer 14. Since the phosphor layer 11 is sealed by the sealing sheets 12A and 12B including a water vapor barrier layer 122 held between resin sheets 121A and 121B, water vapor is prevented from entering into the phosphor layer, and a chemical reaction is less likely to be generated between the phosphor layer 11 and the water vapor barrier layer 122.