The moustached tamarin (Saguinus mystax) is a small primate species found primarily in the tropical forests of the Amazon Basin in South America, particularly in parts of Peru, Brazil, and Bolivia. It is a member of the Callitrichidae family, which includes marmosets and other tamarins.

True to its name, the moustached tamarin has a striking white moustache contrasting with its darker fur, making it easily recognisable.

Their bodies are mainly black or dark brown, with lighter fur around the chest and moustache.

Moustached tamarins are highly social animals, living in small groups that typically consist of 4 to 15 individuals. They are cooperative breeders, meaning that only one female in the group usually breeds while others assist in rearing the offspring. These tamarins are diurnal (active during the day) and arboreal (tree-dwelling), moving quickly and skilfully through the canopy.