Luang Namtha (Lao ຫລວງນໍ້າທາ, literally "Royal Sugar Palm" or "Royal Green River") is a province of Laos located in the north of the country. From 1966 to 1976 it formed, together with Bokeo, the province of Houakhong. Luang Namtha Province covers an area of 145,289 square kilometres (56,096 sq mi). Its provincial capital is Luang Namtha. The province borders with Yunnan, China to the north, Oudomxai Province to the east and southeast, Bokeo Province to the southwest, and Kachin State, Burma to the northwest.
The province contains the Nam Ha National Biodiversity Conservation Area and is one of the main sugar cane and rubber producing areas of Laos with numerous plantations. There are some 20 temples in Muang Sing, including Wat Sing Jai and Wat Namkeo. The anthropological Luang Namtha Museum is located in Luang Namtha.