Prosecution criticised over video showing trial official celebrating Saddam hanging.
He said the court also upheld the death sentences against two other accused, Sultan Hashim, Saddam’s former defence minister, and Hussein Rashid, the former deputy commander of operations for the Iraqi military.
Al-Majid, once among the most powerful and feared men in Iraq, ordered the use of mustard gas and nerve agents against the Kurds, who had allegedly collaborated with the Iranians during the 1980-1988 Iran-Iraq war.
Al-Majid is currently facing trial for his role in crushing a Shia rebellion in southern Iraq in the aftermath of the 1991 Gulf War.
Prosecutors have said he can be executed before the latest trial is completed.
Sentences to life in jail were upheld against Farhan Mutlaq Saleh, the former deputy director of operations for the armed forces, and Sabir al-Douri, former director of military intelligence, Munir Hadad, the appellate court judge, said.
Saddam himself was among the defendants when the trial began last August 21.
He was hanged four months later for his role in the deaths of more than 140 Shia Muslims in the town of Dujail in the first trial against major figures from the ousted regime.
Besides Saddam, three other figures from the former regime have been executed – all in the Dujail case.
They include Barzan Ibrahim, Saddam’s half-brother and former intelligence chief, and Awad Hamed al-Bandar, who headed the Revolutionary Court that sentenced the Dujail victims to death.
Both were hanged in January.