The Gabon talapoin (Miopithecus ogouensis), also known as the northern talapoin, is a small species of African monkey native to riparian habitats in Cameroon, Equatorial Guinea, Gabon, the western Republic of the Congo and the far western Democratic Republic of Congo. It may have been introduced to Bioko and the Canary Islands. Classified in the genus Miopithecus, it was given the name Miopithecus ogouensis, based on the River Ogooué, distinguishing it from the other species, the Angolan talapoin, also known as Miopithecus talapoin.

Gabon talapoins are large-headed monkeys with yellow-olive tinted coating and can be differentiated from the Angolan talapoin by its flesh-coloured ears (not blackish). They are always found near watercourses and can dive and swim away when disturbed. Males and females live together in mixed groups, but rarely interact with each other outside of mating season. Females tend to give birth annually during the rainy season, with mating season taking place during the dry season. Its diet constitute of mostly foraged fruits, seeds, leaves and insects, and crops raided from cultivated plantations. The Gabon talapoins are dependent on thick coverings to protect them from predation due to their small size, but their elusiveness have also made it difficult to observe their behaviors in the wild.

The Gabon talapoin is considered as Near Threatened on the IUCN Red List of Threatened Species. Assessed in 2017, its overall population trend is decreasing, with a continuing decline of mature individuals. Conservation efforts have been made to preserve its habitat and control trade on an international level.

The Gabon talapoin is classified under the Cercopithecidae family, and is one of the only two species under the Miopithecus genus, with the other being the lesser known Miopithecus talapoin, also commonly known as the Angolan talapoin.

The Miopithcus genus was considered monotypic until 1969, when Machado suggested there was a northern and southern species separated by the Congo River. The southern species was described as M. talapoin and the northern species was left undescribed. It was not until 1997 that Jonathan Kingdon gave it the scientific name Miopithecus ogouensis, based on the Ogooué River in Gabon. Kingdon pointed out that the presently used binomial, where the specific name is a reference to the Ogooué River, is a nomen nudum:

However, it can be argued that his description is valid per ICZN rules, as he included an illustration (thereby possibly providing a valid type), a description, and specifically said the name was intended for this new species, leading later authorities to accept it.

Female Gabon talapoins have a head and body length ranging from 230–340 millimetres (9.1–13.4 in), and weigh 0.8–1.2 kilograms (1.8–2.6 lb). Males are larger and take six years to reach full adult size, with head and body length ranging from 260–360 millimetres (10–14 in), and weigh 1.0–1.72 kilograms (2.2–3.8 lb). Gabon talapoins have an average tail length ranging from 310–450 millimetres (12–18 in). Infants weigh approximately 180 grams (6.3 oz) at birth, and the size of a newborn's head is almost as big as its body.

Gabon talapoins are the smallest of the Old World monkey and are considered as dwarf guenons. They are large headed, and unlike the related Angolan talapoin, the Gabon talapoin has flesh-coloured (not blackish) ears and facial skin. There are no distinct colour differences between mature males and females and the young. The Gabon talapoin is short furred, and has a vivid, grizzled yellow-olive crown and back, with golden-yellow coating to its thin limbs, and a dark tipped tail. Its eyelids and lips are yellowish in colour, with noticeable dark streaks on its nose and cheeks. They also have cheek pouches that are useful for storing food. Females have a pink sexual swelling, and males are characterized by their large pale blue scrotum.