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 Lophocebus species are more closely related to the baboons in genus Papio, while the Cercocebus species are more closely related to the Mandrill. The single species in Rungwecebus was discovered recently.
The three genera of mangabeys are:
- Lophocebus, the crested mangabeys
- Rungwecebus, the highland mangabey
- Cercocebus, the white-eyelid mangabeys