A color conversion substrate and a display device are provided. The color conversion substrate includes a base substrate, a first color filter and a second color filter disposed on a surface of the base substrate, a first partition layer disposed between the first color filter and the second color filter, a second partition layer disposed on the first partition layer, a first wavelength conversion pattern disposed on the first color filter and a second wavelength conversion pattern disposed on the second color filter, wherein the first partition layer includes a first lower surface disposed on the first color filter and a second lower surface disposed on the second color filter.