Juruena National Park, Protected rainforest reserve in northern Mato Grosso and southern Amazonas, Brazil.

Juruena National Park covers 1,958,203.56 hectares along the Juruena River in northern Mato Grosso and southern Amazonas, making it Brazil's third-largest national park. About 49% of its terrain is flat plain, 18% gently undulating, 21% undulating, 10% strongly undulating and 1% mountainous, with altitudes from 39 to 457 metres. Its rivers, including the São Tomé and Sucunduri, are clear-water systems with rapids and waterfalls.

Juruena National Park was created by decree on 5 June 2006 and is administered by the federal Chico Mendes Institute for Biodiversity Conservation. It is one of the parks established under the Amazon Region Protected Areas Programme (ARPA), launched in 2002. In 2014 the federal government considered declaring the park a public utility area to build the São Simão Alto and Salto Augusto Baixo dams, with a forecast capacity of 4,940 MW; after a WWF-Brasil campaign against a project that would have flooded over 40,000 hectares, the proposal was withdrawn in September 2014.

The park lies in the lower Juruena–Teles Pires and upper Tapajós region, and its name comes from the Juruena River that runs along it. The river's clear waters turn green or olive-green in the dry season and muddy in the rainy season. The park's stated aims include environmental education and interpretation alongside scientific research.

Entry to the park requires permits from the Chico Mendes Institute for Biodiversity Conservation, which must be arranged in advance. Planning your visit ahead of time will ensure you have the necessary authorization to explore the reserve.

Of the 412 bird species recorded, at least 26 are restricted to the Madeira–Tapajós interfluvium, among them the bald parrot (Pyrilia aurantiocephala) and the tooth-billed wren (Odontorchilus cinereus). The park also protects jaguar, giant otter and harpy eagle.