The term mangabey can refer to three different genera of Old World monkeys. Lophocebus and Cercocebus were once thought to be very closely related, so much so that all the species were in one genus. However, it is now understood that the species within genus Lophocebus are more closely related to the baboons in genus Papio, while the species within genus Cercocebus are more closely related to the Mandrill. The single species in Rungwecebus was discovered recently.
The three genera of mangabeys are: