Campbell's mona monkey (Cercopithecus campbelli), also known as Campbell's guenon and Campbell's monkey, is a species of primate in the family Cercopithecidae found in the Ivory Coast, Gambia, Ghana, Guinea, Guinea-Bissau, Liberia, Senegal, and Sierra Leone. It was named for Henry Dundas Campbell, in 1838. Lowe's mona monkey was previously considered a subspecies of Campbell's mona monkey.