Langkasuka was an ancient Malayic Hindu-Buddhist kingdom located in the Malay Peninsula.^[25] The name is Sanskrit in origin; it is thought to be a combination of langkha for "resplendent land" -sukkha for "bliss". The kingdom, along with Old Kedah, is among the earliest kingdoms founded on the Malay Peninsula. The exact location of the kingdom is of some debate, but archaeological discoveries at Yarang near Pattani, Thailand suggest a probable location.

The kingdom is proposed to have been established in the 1st century, perhaps between 80 and 100 CE.^[26] It then underwent a period of decline due to the expansion of Funan in the early 3rd century. In the 6th century it experienced a resurgence and began to send emissaries to China. King Bhagadatta first established relations with China in 515 CE, with further embassies sent in 523, 531 and 568.^[27] By the 8th century it had probably come under the control of the rising Srivijaya Empire.^[28] In 1025 it was attacked by the armies of King Rajendra Chola I in his campaign against Srivijaya. In the 12th century, Langkasuka was a tributary to Srivijaya.

The kingdom declined and how it ended is unclear with several theories being put up. The late 13th-century Pasai Annals, mentioned that Langkasuka was destroyed in 1370. However, other sources mentioned Langkasuka remained under the control and influence of the Srivijaya Empire until the 14th century when it was conquered by the Majapahit Empire. Langkasuka was probably conquered by Pattani as it ceased to exist by the 15th-century. Several historians contest this and believe that Langkasuka survived up to the 1470s. The areas of the kingdom that were not under the direct rule of Pattani is thought to have embraced Islam along with Kedah in 1474.^[29]

The name may have been derived from langkha and Ashoka, the legendary Mauryan Hindu warrior king who eventually became a pacifist after embracing the ideals espoused in Buddhism, and that the early Indian colonizers of the Malayic Isthmus named the kingdom Langkasuka in his honour.^[30] Chinese historical sources provided some information on the kingdom and recorded a king Bhagadatta who sent envoys to the Chinese court. There were numerous Malay kingdoms in the 2nd and 3rd centuries, as many as 30, mainly based on the eastern side of the Malay peninsula.^[31] Langkasuka was among the earliest kingdoms.