Nuon Chea (Khmer: ??? ??; born Lao Kim Lorn; 7 July 1926 – 4 August 2019), also known as Long Bunruot (Khmer: ??? ????????) or Rungloet Laodi (?????? ????? Thai: ???????? ???????), was a Cambodian politician who was the chief ideologist of the Khmer Rouge.
He also briefly served as acting Prime Minister of Democratic Kampuchea.
He was commonly known as "Brother Number Two" (Khmer: ???????), as he was second-in-command to Khmer Rouge leader Pol Pot, General Secretary of the Party, during the Cambodian genocide of 1975–1979.
In 2014, Nuon Chea received a life sentence for crimes against humanity, alongside another top-tier Khmer Rouge leader, Khieu Samphan, and a further trial convicted him of the crime of genocide in 2018.