An illumination system is housed in a footwear, the footwear including a sole and an upper. An interfacing layer and a liner form inner interior layers connected to the upper. A plurality of illumination sources are electrically connected to a power source and positioned adjacent to the liner. The illumination sources are positioned between the liner and upper. The upper has a light diffusing section. The light emitted from the plurality of illumination sources is diffused as it passes through the light diffusing section of the upper. Aesthetic designs can be creating, either through the arrangement of the plurality of illumination sources or the provision of a light impermeable section on the upper. The light impermeable section, in combination with the light diffusion section, can be used to form or outline an aesthetic design. The result is an internally illuminated footwear with diffused light.