Moazzam Begg is one of nine British Muslims who were held in extrajudicial detention in the Guantanamo Bay detainment camp, in Cuba, by the government of the United States of America. He was released on January 25, 2005 along with Feroz Abbasi, Martin Mubanga and Richard Belmar, without charge though he received no compensation or an apology.

President Bush had released Moazzam Begg over the objections of the Pentagon, the CIA, and the FBI, who alleged that Mr. Begg could be dangerous terrorist. After his release from Guantanamo, Begg appeared in the Islamist propaganda video "21st Century CrUSAders" and said the War on Terrorism is really a war against Islam. He has since toured as a speaker about his time in Guantanamo and other detention facilities, characterizing the British response to terrorism as racist.