Nam Et-Phou Louey National Protected Area (NPA) is a protected area in northern Laos, covering 5,959 km² in three provinces: Houaphan, Luang Prabang, and Xieng Khouang. The park includes a 3,000 km² core area where human access and wildlife harvest is prohibited and a 2,950 km² buffer area where pre-existing villages are allocated land for subsistence living.

The park consists mainly of mountains and hills, with elevations ranging between 336 and 2257 meters. The area is the source of many rivers. It is named after the Nam Et River and Phou Louey Mountain (‘Forever Mountain’). The area has a high level of biodiversity and endangered species including tiger, leopard, clouded leopard, Asian golden cat, marbled cat, civet, gaur, Sambar deer, white-cheeked gibbon, sun bear, black bear, Asian elephant, dhole, horn-bill and three species of otter.

Villagers living in the Nam Et-Phou Louey National Park include Tai Dam, Tai Daeng, Tai Kao, Tai Puan, Tai Lue, Tai Yuan, Khmu, Hmong Kao, Hmong Lai, and Yao.

Viengthong, a small town in Houaphan Province, is the site of the Nam Et-Phou Louey NPA headquarters and visitor centre, where tours into the park can be organised. The town has basic accommodation and a handful of restaurants. There are many biking and walking trails, as well as hot springs.