According to some embodiments of the present disclosure, a display device includes: a substrate; a planarization layer on the substrate; a first alignment mark in a non-display area of the substrate; a first electrode and a second electrode in a display area of the substrate; a light emitting element electrically connected to the first electrode and the second electrode; a wavelength conversion layer on the light emitting element; a first bank on at least a part of the first electrode; and a second bank on the first bank to be around the wavelength conversion layer. A thickness of a part of the planarization layer that overlaps the first alignment mark in a thickness direction of the substrate is greater than a thickness of a part of the planarization layer that overlaps the first electrode and the second electrode in the thickness direction of the substrate.