The display device includes a substrate, a patterned wall, the first, second, third sub-pixels, and an optical layer. The patterned wall is disposed on the substrate and has a plurality of openings. The first sub-pixel is disposed in one of the openings and includes a light-emitting element and a wavelength conversion layer. The second sub-pixel is disposed in one of the openings and includes a light-emitting element and a wavelength conversion layer. The third sub-pixel is disposed in one of the openings and includes a light-emitting element and a wavelength conversion layer, wherein a first distance between a top surface of the light-emitting element and a top surface of the patterned wall is about 10 um to about 100 um. The optical layer is disposed on the patterned wall and in direct contact with at least one of the first sub-pixel, the second sub-pixel, and the third sub-pixel.