Shan State (Shan: မိူင်းတႆး, Möng Tai; Burmese: ရှမ်းပြည်နယ်, pronounced [ʃáɰ̃ pjìnɛ̀]) is a state of Myanmar. Shan State borders China (Yunnan) to the north, Laos (Louang Namtha and Bokeo Provinces) to the east, and Thailand (Chiang Rai, Chiang Mai and Mae Hong Son provinces) to the south, and five administrative divisions of Myanmar in the west (Kachin State, Mandalay Region, Kayin State, Kayah State, and Sagaing Region). The largest of the 14 administrative divisions by land area, Shan State covers 155,800 km², almost a quarter of the total area of Myanmar. The state gets its name from the Burmese name for the Tai peoples: "Shan people". The Tai (Shan) constitute the majority among several ethnic groups that inhabit the area. Shan State is largely rural, with only three cities of significant size: Lashio, Kengtung, and the capital, Taunggyi. Taunggyi is 150.7 kilometres (93.6 mi) northeast of the nation's capital Naypyitaw.

The Shan state, with many ethnic groups, is home to several armed ethnic groups. While the military government has signed ceasefire agreements with most groups, vast areas of the state, especially those east of the Salween River, remain outside the central government's control, and in recent years have come under heavy ethnic-Han Chinese economic and political influence. Other areas are under the control of military groups such as the Shan State Army.

According to data from the United Nations Office on Drugs and Crime (UNODC), Shan State is the region that produces the most opium in Myanmar, though production declined through the mid-to-late 2010s.

Muang Dai (Shan: မိူင်းတႆး) is the native name for the region as well as a term used for the Tai-inhabited parts of Myanmar outside of Shan State. Muang (မိူင်း) means country in Tai languages and is used before the names of other countries, e.g. Muang Maan (Myanmar).

Shan Pyi (Burmese: ရှမ်းပြည်) derives from a Burmese corruption of the name Siam which is an old name for Lower Thailand. Pyi is a Burmese word meaning country and thus Shan Pyi can be translated as Shan State. Officially, the region is called Shan State in English and Shan Pyine in Burmese but the ne in often dropped in colloquial speech.

Shanland alongside Muang Dai are often used in political and nationalist dialogue when referring to the region.

Shan State is the unitary successor state to the Burmese Shan States, the princely states that were under some degree of control of the Irrawaddy valley-based Burmese kingdoms.

Historical Tai-Mao states extended well beyond the Burmese Shan States, ranging from full-fledged kingdoms of Assam in the northwest to Lan Xang in the east, to Lan Na and Ayutthaya in the southeast, as well as several petty princely states in between, covering present-day northern Chin State, northern Sagaing Region, Kachin State, Kayah State in Myanmar as well as Laos, Thailand and the southwestern part of Yunnan, China. The definition of Burmese Shan States does not include the Ava Kingdom and the Hanthawaddy kingdom of the 13th to 16th centuries, although the founders of these kingdoms were Burmanized Shans and Monized Shans, respectively.^{[citation needed]}