Muang Sing or Mueang Sing is a small town and district (muang) in Luang Namtha Province, northwestern Laos, about 60 kilometres northwest of the town of Luang Namtha and 360 kilometres northwest of Vientiane.

It lies in very close proximity to the border with Yunnan, China, surrounded by mountains and rivers. A notable Buddhist centre, with a dramatic growth in temples since the 1980s, it is popular with trekkers in northern Laos.

The principal temple of some 20 in Muang Sing is the Wat Sing Jai or Wat Xieng Jai, located behind the Muangsing Guest House. The monastery, painted in hues reminiscent of the Caribbean, has a museum, but because its items are of high local value, it is closed to visitors for fear of theft.
Another major temple is the Wat Namkeo. The wihan in the town are typically multi-tired roofed buildings typical of northern Laos, but most houses have corrugated metal roofs and wooden beams, reflecting a lack of wealth in the area.




The Buddhas, however, are golden, and typically have large long earlobes, commonly seen in Sipsongpanna and Shan State of Burma.

On the main market in Muang Sing Yunnanese traders sell goods such as Western clothing, fake sports clothing and gear, electrical and household appliances and cooking oil, and local ethnic people sell mostly vegetables, fruits, herbs and spices.