Display device and tiled display device including the same

A display device includes a substrate including a display area including emission areas and a light blocking area; and a non-display area adjacent to the display area; a thin-film transistor layer disposed on the substrate and including thin-film transistors; a light-emitting element layer disposed on the thin-film transistor layer and including light-emitting elements; a wavelength conversion layer disposed on the light-emitting element layer that converts a peak wavelength of a light from at least a part of the of light-emitting elements; and a color filter layer disposed on the wavelength conversion layer, and including color filters corresponding to the emission areas and a first light blocking part corresponding to the light blocking area and the non-display area. A transmittance of the first light blocking part with respect to a light having a wavelength of about 1000 nm or more is about 80% or more.