Rüppell's fox is a small fox, measuring in total length, including a tail measuring long. There is no pronounced sexual dimorphism, but males appear slightly larger than females. Both sexes are reported to have an average weight of . The coat is sandy in color, ticked with numerous white hairs, and fading from reddish along the middle of the back to pure white on the animal's underparts and on the tip of its tail. The flanks are also paler. The head has a more rusty tone on the muzzle and forehead, with dark brown patches on the sides of the muzzle, stretching up towards the eyes. The chin and the sides of the face are white. The whiskers are long, reaching .