Thailand (/ˈtaɪlænd/ TY-land), officially the Kingdom of Thailand and formerly known as Siam, is a unitar state at the centre of the Indochinese peninsula in Southeast Asia composed of 76 provinces. At 513,120 km2 and over 68 million people, Thailand is the world's 50th largest country by total area and the 21st-most-populous country. The capital and largest city is Bangkok, a special administrative area. Thailand is bordered to the north by Myanmar and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and the southern extremity of Myanmar.

Its maritime boundaries include Vietnam in the Gulf of Thailand to the southeast, and Indonesia and India on the Andaman Sea to the southwest. Even though constitutional monarchy and parliamentary democracy form of government was established in 1932, the most recent coup d'état in 2014 made Thailand a de facto military dictatorship. Its current constitution was ratified on April 6, 2017, during military junta's watch.