The northern pig-tailed macaque (Macaca leonina) is a species of macaque in the family Cercopithecidae. It is found in Bangladesh, Cambodia, China, India, Laos, Myanmar, Thailand, and Vietnam. Traditionally, M. leonina was considered a subspecies of the southern pig-tailed macaque (M. nemestrina), but is now classified as individual species.
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 in 2008. Like its southern cousin it is used for harvesting coconuts in Thailand.
Although no global population estimate is available, some site-based estimates are, including Keo Seima Wildlife Sanctuary in Cambodia, where an increasing population of almost 4,000 is reported.