Ramadan was part of the same trial as deposed leader Saddam Hussein involving the killing of 148 Shiite men in the city of Dujail after a plot to assassinate Saddam failed in 1982.
On Nov. 5, Ramadan was sentenced to life in prison but an official with the court told Kuwait's KUNA news agency the death sentence was "more proportionate" to the crimes.
Saddam and two other codefendants were found guilty and on Dec. 30, Saddam was executed by hanging. The other two were executed Jan. 15.
In London, the Amnesty International rights group issued a statement denouncing the appeal court's change of Ramadan's sentence, saying "the affair was a mockery, one which will make it all the harder to establish the rule of law and justice in Iraq after the decades of tyranny."