Omar Abdel-Rahman, the so-called Blind Sheikh, was arrested in 1993 and convicted in 1995 along with nine followers of conspiracy to blow up the United Nations and several New York landmarks.
He was serving a life sentence in prison when he died on Saturday.
Abdel-Rahman was the spiritual leader of Gamaa Islamiya, the most feared militant group in Egypt in the 1980s and 1990s. He fled to the United States in 1990.