Johnston's mangabey (Lophocebus johnstoni ) is a species of crested mangabey in the family Cercopithecidae. It had been considered a subspecies of the gray-cheeked mangabey (L. albigena ), but in 2007 was given the status of species by Colin Groves, with Osman Hill's mangabey (L. osmani ) and the Uganda mangabey (L. ugandae ).