The bush dog Speothos venaticus, a short-legged, medium-sized Neotropical canid, remains elusive despite its wide geographical range. We present the first documented occurrence of this species within Rio Doce State Park, Minas Gerais state, Brazil. This Park is a unique, well-preserved area with a diverse array of mammal species, a rarity in the fragmented Atlantic Forest. We recorded the bush dog after 7,744 camera-trap days near Lagoa dos Patos, one of the Park’s lakes. This new record is a significant range extension for the species within the Atlantic Forest of Minas Gerais state, as the nearest known record is c. 420 km to the south. The new record is the northernmost documented occurrence of the bush dog in the Brazilian Atlantic Forest. This finding is a significant addition to the Park’s mammalian carnivore community, and underscores its importance as high-quality habitat for rare species such as the bush dog, and its value for scientific research and biodiversity conservation.