The pileated gibbon (Hylobates pileatus) is a primate in the gibbon family, Hylobatidae.

The pileated gibbon has sexual dimorphism in fur coloration: males have a purely black fur, while the females have a white-grey colored fur with only the belly and head black. The white and often shaggy hair ring around the head is common to both sexes.

The species has been identified as Endangered, and is listed in CITES Appendix I. Their main threat is habitat destruction, with the wild forest they live in being converted into farmland. This has led to local extinction in some areas. Also, like many other species of primate, they are hunted and captured for meat and to be sold into Wildlife smuggling. Many attempts have been made to survey and increase the species' numbers, both concerning their status in the wild, and in zoos.

The range of the pileated gibbon is eastern Thailand, western Cambodia and southwest Laos. Its lifestyle is much like other gibbons: diurnal and arboreal, it lives together in a monogamous pair, brachiates through the trees with its long arms, and predominantly eats fruits, leaves and small animals. Reproduction habits are not well known, but are presumed to be similar to the other gibbons. Mating pairs also mark their own territory together, with the female and male performing loud vocalisations to show this.

The pileated gibbon is found in the following areas. There are about 35,000 individuals in Cambodia and about 30,000 in Thailand.

• Khao Yai National Park, Thailand

• Thap Lan National Park, Thailand

• Khao Ang Ru Nai Sanctuary, Thailand

• Khao Soi Dao Sanctuary, Thailand

• Pang Sida National Park, Thailand

• Ta Phraya National Park, Thailand

• Cardamom Mountains, Cambodia (about 20,000 individuals)

• Bokor National Park, Cambodia (about 1,000 individuals)