Hem Heng (Khmer: ហែម ហេង; born 8 November 1951) is a Cambodian diplomat who was the Cambodian ambassador to the United States from 2008 to 2015. Prior to his appointment, Heng served as an adviser to foreign minister Hor Namhong and has worked in the Ministry of Foreign Affairs. He has had more than 30 years' experience in foreign affairs.