The collared mangabey, also called red-capped mangabey and white-collared mangabey, is a species of primate in the family Cercopithecidae of Old World monkeys. It formerly included the sooty mangabey as a subspecies. As presently defined, the collared mangabey is monotypic.

Old World monkeys are primates in the family Cercopithecidae. Twenty-four genera and 138 species are recognized, making it the largest primate family. Old World monkey genera include baboons, red colobus and macaques. Common names for other Old World monkeys include the talapoin, guenon, colobus, douc, vervet, gelada, mangabey, langur, mandrill, surili (Presbytis), patas, and proboscis monkey.