Kuy, also known as Kui, Soui or Kuay (Thai: ภาษากูย; Khmer: ភាសាកួយ), is a Katuic language, part of the larger Austroasiatic family spoken by the Kuy people of Southeast Asia.
Kuy is one of the Katuic languages within the Austroasiatic family. It is spoken in Isan, Thailand by about 300,000 people, in Salavan, Savannakhet and Sekong Provinces of Laos by about 64,000; and in Preah Vihear, Stung Treng and Kampong Thom Provinces of northern Cambodia by 15,500 people.
Spelling variants and varieties include the following (Sidwell 2005:11).
Van der haak & Woykos (1987-1988) identified two major Kui varieties in Surin and Sisaket provinces of eastern Thailand, Kuuy and Kuay. Van der haak & Woykos also identified the following divergent Kui varieties in Sisaket Province, Thailand.