The following outline is an overview of and topical guide to Thailand.
Thailand is a country at the centre of the Indochina peninsula in Southeast Asia, known as Siam until 1939. As of 2023[update] Thailand is a monarchy governed by a military junta that took power in May 2014. Although a constitutional system was established in 1932, the monarchy and military have continued to intervene periodically in politics. Thailand experienced rapid economic growth between 1985 and 1996, becoming a newly industrialized country and a major exporter. Manufacturing, agriculture, and tourism are leading sectors of the economy. Among the ten ASEAN countries, Thailand ranks second in quality of life and the country's HDI had been rated as "high". Its large population and growing economic influence have made it a middle power in the region and around the world.
Tai groups and people who speak Tai are the majority population in Thailand, with Tai-Lao speakers making up 25% of the population. The heartland of Thailand is the Chao Phraya River Valley, where the original inhabitants were Mon-speaking people. The Mon people are now a minority, and the Mon language is endangered. The valley later gained control over Eastern Thailand as well, known as the Korat Plateau. This area is not mountainous, as its name would suggest. Although the people of this area have largely adopted Thai culture, there is still a mixture of many Tai-Kadai, Khmer, and Cambodian speakers. Northern Thailand is mountainous and holds many minority groups: "hill tribes." Another mountainous region is the Malay Peninsula, where the 3rd largest population of Malay people live. Many in this area speak Mon-related languages.