Most monkeys are omnivores. Encyclopaedia Britannica states that most monkey species are omnivorous, with diets that include both plant and animal matter. Typical foods include fruits, flowers, leaves, nuts, seeds, insects, small animals, and sometimes birds’ eggs.
Diet still varies by species and lifestyle: smaller or more insect-focused primates may take more animal prey, while larger diurnal monkeys often eat more vegetation. Specialized groups such as colobines lean heavily toward leaves, but the broad answer for monkeys as a group is omnivore—not strict herbivore or carnivore.