Ieng Sary (born 1922, 1925 or 1929) was the foreign minister of Cambodia from 1976 to 1979 and a powerful figure in the Khmer Rouge. He was also the deputy prime minister of Cambodia during the Khmer Rouge regime, which lasted from 1975 to 1979.

He was born in Vietnam and had the name Kim Trang until he changed his name when joining the Khmer Rouge. He was the brother-in-law of Khmer Rouge leader Pol Pot. Ieng was a leader of the Khmer Rouge guerilla war against the government from 1993 until he surrendered to the government in 1996 and was granted amnesty. He suffered a heart attack in July 2004 and was taken to Thailand for medical treatment.