Nguyễn Trần Duy Nhất (born March 21, 1989) is a Vietnamese professional Muay Thai, Kun Khmer and Lethwei fighter. Duy Nhất is a five-time WMF Muay Thai world champion and four-time SEA Games medalist in Muay Thai; in addition to having won medals at the IFMA World Muaythai Championships, Asian Indoor and Martial Arts Games, Asian Martial Arts Games, Asian Indoor Games, and Asian Beach Games.