A vehicle sill illumination assembly has a main body, an illumination panel and a controller. The main body includes a first portion, a second portion and a third portion that together define an inverted U-shaped structure as viewed in cross-section. The first portion has an upright surface. The second portion extends horizontally inboard from an upper edge of the first section. The third portion extends downward from an inboard side of the second portion. The illumination panel is installed to an area of the first portion of the main body such that the illumination panel faces in an outboard direction with the main body installed to a vehicle sill structure. The controller is located within the main body and is configured to control illumination of the illumination panel.