The Northern pig-tailed macaque (Macaca leonina), is a species of macaque in the Cercopithecidae family. It is found in Bangladesh, Cambodia, China, India, Laos, Myanmar, Thailand, and Vietnam. Traditionally, it has been considered a subspecies of the Southern pig-tailed macaque. In India, it is found in south of the Brahmaputra River, in the northeastern part of the country. Its range in India extends from Assam and Meghalaya to eastern Aruanchal Pradesh, Nagaland, Manipur, Mizoram and Tripura. A detailed report on the ecology and behaviour of northern pig-tailed macaque has been published recently.