The Dja River (also known as the Ngoko River) is a stream in west-central Africa. It forms part of Cameroon–Republic of Congo border and has a course of roughly 720 kilometres (450 mi).^[1]

Rising southeast of the southeastern Cameroon town of Abong-Mbang, the Dja Faunal Reserve, which was named a UNESCO World Heritage Site in 1987, lies along the banks of its upper course.^[1] It protects one of the largest tracts of tropical rainforest in Africa.^[1] Forming its natural boundary, and almost completely encircling the reserve (except to the south-west), cliffs run along the course of the river in the south part of the reserve for 60 km and are associated with a section of the river which is broken by rapids and waterfalls.^[2] Following its course in the reserve, the Dja flows approximately southeast past Moloundou, below which small boats can navigate.^[1] At Ouésso, in the Republic of Congo, it empties into the Sangha River.^[1]

Every year, poachers travel up the Dja for central Nki National Park, where elephant ivory is abundant.^[3] Strong currents on the river are a deterrent for half the year, but after that, according to freelance journalist Jemini Pandya, the fauna is easy to prey upon.^[3]