Northern Khmer people (Khmer: ជនជាតិខ្មែរខាងជើង; Thai: เขมรเหนือ) or colloquially as Thais of Khmer origin (Thai: ชาวไทยเชื้อสายเขมร); mostly referred to as Khmer Surin (Khmer: ខ្មែរសុរិន្ទ Thai: เขมรสุรินทร์) is the designation used to refer to ethnic Khmers native to the Isan region of Northeast Thailand.
The Khmer people (Khmer: ជនជាតិខ្មែរ, UNGEGN: Chônchéatĕ Khmêr, ALA-LC: Janajāti Khmaer [cɔn.ciət kʰmae]) are an ethnic group native to Cambodia. They comprise over 95% of Cambodia's population of 17 million. They speak the Khmer language, which is part of the larger Austroasiatic language family alongside Mon and Vietnamese.
The majority of Khmer people follow Theravada Buddhism. Significant populations of Khmers reside in neighboring regions, including Northern Khmer communities in adjacent areas of Thailand and Khmer Krom communities in the Mekong Delta region of Vietnam. There are nearly one million Khmers in other diaspora communities, living mainly in the United States, France, and Australia.
Thailand is a country of some 70 ethnic groups, including at least 24 groups of ethnolinguistically Tai peoples, mainly the Central, Southern, Northeastern, and Northern Thais; 22 groups of Austroasiatic peoples, with substantial populations of Northern Khmer and Kuy; 11 groups speaking Sino-Tibetan languages ('hill tribes'), with the largest in population being the Karen; 3 groups of Austronesian peoples, i.e., the Malay, the majority ethnic group in the southernmost three provinces, together with the Moken and Urak Lawoi ('sea gypsies'); and both groups of Hmong-Mien. Other ethnic groups include longstanding immigrant communities such as the Chinese, Indians, Persian, and Portuguese.