A display device includes an optical filter substrate including: a substrate; a first color filter on the substrate; a second color filter on the substrate, the second color filter spaced apart from the first color filter; a first color conversion element on the first color filter, the first color conversion element converting incident light into light of a first color; a second color conversion element on the second color filter, the second color conversion element converting the incident light into light of a second color; and a black matrix located between the first color conversion element and the second color conversion element, and between the first color filter and the second color filter.