An illumination assembly for illuminating drawers of a storage unit, such as a cabinet or toolbox. The illumination assembly is adapted to be coupled to the storage unit by coupling the illumination assembly within a retrofittable or integrated feature of the storage unit to direct or radiate light into a containment space (such as a drawer) of the storage unit when opened. The illumination assembly may also illuminate a facade, sides, underside, or surrounding area of the storage unit.