Chalcides colosii, also known commonly as the Riffian skink and Colosi's cylindrical skink, is a moderate-sized species of lizard in the family Scincidae. The species is native to Morocco and some Spanish territories in northwestern Africa. It is named after Giuseppe Colosi, former director of the Zoological Institute of the University of Florence. It has been considered a subspecies of Chalcides ocellatus. The females of the species give birth to live young.