Muang Sing is a small town and district located in the Luang Namtha Province of northwestern Laos. It is situated approximately 60 kilometers northwest of the town of Luang Namtha and roughly 360 kilometers northwest of the capital city, Vientiane.
The area is characterized by its geography, as it is surrounded by mountains and rivers. Due to its location very close to the border with Yunnan, China, Muang Sing has a history as a major producer of opium. The town continues to face challenges related to drug production and smuggling resulting from its proximity to both China and Myanmar.