Khairat al-Shater, the deputy head of the Muslim Brotherhood, was among the 10 hopefuls whose appeals were rejected Tuesday by Egypt's electoral commission.
The commission said al-Shater was disqualified because of his 2006 prison sentence handed down by a military court. His attorney, however, said the decision was a political move to rig the election.
The Muslim Brotherhood, a potent force in the new political landscape in Egypt, will be represented in the election by Mohamed Morsi, the head to the organization's Freedom and Justice Party.
The Financial Times called Morsi "an uncharismatic figure" who nevertheless was a likely favorite in the election, the first since the ouster of longtime President Hosni Mubarak.
Also disqualified were ultra-conservative Islamist leader Hazem Abu Ismail and Omar Suleiman, the former head of Egypt's intelligence service. Officials said Monday that Suleiman may have used forgery and improper pressure to drum up support for his candidacy.