Types of Monkeys: A Complete Guide to Every Major Group

Monkeys are the most varied group of primates on the planet, spanning more than 250 recognised species that range from a squirrel-sized marmoset to a powerfully built mandrill. Understanding the different types of monkeys is the foundation for everything else: where they live, what they eat, how they behave, and why some species adapt to human company far better than others.

What Actually Counts as a Monkey?

A monkey is a primate that sits outside the ape lineage but inside the group known as simians. In practical terms, monkeys usually have tails, comparatively narrow chests, and a skeleton built for moving along branches rather than hanging beneath them. Apes such as chimpanzees, gorillas and orangutans have no tail, broader shoulders and larger brains relative to body size, which is why the distinction matters so much in the comparison between monkeys and apes.

Scientists divide living monkeys into two broad families that separated tens of millions of years ago. That single split explains most of the physical and behavioural differences you will notice, and it is explored in depth in our guide to Old World versus New World monkeys.

Old World Monkeys

Old World monkeys live across Africa and Asia. They have downward-facing nostrils set close together, hardened sitting pads, and tails that are never prehensile, meaning the tail is used for balance rather than gripping. Many species spend a good deal of time on the ground.

• Macaques – the most widespread monkey genus after humans spread them further, famous for problem solving and adaptability. See our macaque profiles.
• Guenons and vervets – slender, colourful African forest and savanna monkeys covered in our guide to African monkeys.
• Baboons and mandrills – large, ground-dwelling species with complex hierarchies, discussed further in largest monkeys on Earth.
• Colobus monkeys and langurs – leaf specialists with multi-chambered stomachs, many of them found in Asia.

New World Monkeys

New World monkeys are found from southern Mexico down through Central and South America. Their nostrils face sideways, they are almost entirely tree-dwelling, and several groups evolved a prehensile tail that works like a fifth limb. Body size skews smaller, and family groups are often tight-knit.

• Capuchins – the celebrated tool users of the Americas and the subject of our capuchin species pages.
• Marmosets and tamarins – the miniatures of the primate world, described in smallest monkey species.
• Squirrel monkeys – fast, highly social canopy foragers that live in large troops.
• Spider and howler monkeys – long-limbed acrobats and the loudest land mammals in the Americas, both profiled in South American monkeys.
• Owl monkeys – the only truly night-active monkeys, covered in nocturnal monkeys.

Grouping Monkeys by Lifestyle

Taxonomy is only one lens. Keepers, field biologists and conservationists often group monkeys by how they live, because that is what shapes their daily needs.

By habitat

Rainforest canopy species, mangrove and swamp specialists, montane forest dwellers, savanna troops and rock-dwelling species all face different pressures. Our guides to monkey habitats and where monkeys live break this down region by region.

By diet

Some monkeys are fruit specialists, others gum feeders, insect hunters, leaf eaters or true generalists. Diet drives tooth shape, gut anatomy and troop size, and it is the reason a marmoset and a colobus cannot be fed the same way. Our reference page on what monkeys eat explains the categories in detail.

By activity pattern

Nearly all monkeys are diurnal, with the owl monkeys standing alone as the nocturnal exception. Activity pattern influences vision, colouring and vocal behaviour, which links closely to how monkeys communicate.

Size, Intelligence and Lifespan Vary Enormously

The smallest monkeys weigh little more than a bar of soap, while the largest can exceed 30 kilograms. Cognitive ability varies just as widely, and the species that consistently top the rankings are examined in smartest monkey species and monkey intelligence. Longevity follows a similar spread, from roughly a decade in some small New World species to forty years or more in larger Old World monkeys, as set out in our guide to monkey lifespan.

Which Types of Monkeys Live Alongside People?

A small number of species, chiefly capuchins, marmosets, tamarins, squirrel monkeys and some macaques, are the ones most often kept in human care. Even then, the commitment is closer to raising a permanently toddler-aged family member than owning a pet, and the legal position differs from one state and country to the next. Read is it legal to own a monkey before going any further, then work through our complete beginner guide to monkey care and enclosure building guide.

Frequently Asked Questions

How many types of monkeys are there?

Between 250 and 270 species are currently recognised, split into two families: the Old World monkeys of Africa and Asia and the New World monkeys of the Americas. The exact count keeps rising as genetic work splits populations that were once treated as single species.

What is the difference between a monkey and an ape?

Monkeys almost always have tails, narrower chests and shoulders built for walking along branches. Apes have no tail, broad chests and shoulders built for hanging beneath branches, along with larger brains relative to body size.

Which type of monkey is the most common?

Macaques are the most widespread genus, occupying more countries and habitat types than any other monkey, from tropical islands to snow-covered mountains.

Are lemurs monkeys?

No. Lemurs, lorises and tarsiers are primates but sit outside the monkey and ape group, which is why Madagascar has no true monkeys despite its famous primate fauna.

Where to Go Next

If you want the global overview, start with monkey species around the world. For biology, continue with monkey adaptations and monkey evolution. If conservation is your interest, our pages on endangered monkey species and monkey conservation explain what is at stake and what is being done about it.