The Supreme Patriarch of Thailand or Sangharaja is the head of the order of Buddhist monks in Thailand. His full title is Somdet Phra Saṅgharāja Sakalamahāsaṅghapariṇāyaka.

Dhammayuttika Nikāya, or Dhammayut Order, is an order of Theravada Buddhist bhikkhus (monks) in Thailand, Cambodia, and Burma, with significant branches in the Western world. Its name is derived from Pali dhamma + yutti + ka (group). The order began in Thailand as a reform movement led by a prince who would later become King Mongkut of Siam, before also spreading to Cambodia and Burma. The movement became formally recognized as its own monastic order by the Thai government in 1902, with any Thai Theravada bhikkhus not within the order being referred to as part of the Maha Nikaya order. The Dhammayuttika Nikaya plays a significant political role in Thailand. The order has historically been favored by the Thai government and monarchy, with the order holding the majority of all royal monastic titles in Thailand and most of the Supreme Patriarchs since its founding having come from the Dhammayuttika Nikaya, despite the order making up less than ten percent of all bhikkhus in Thailand.