Ali Hassan al-Majid, a former defense minister, was sentenced to death by hanging for orchestrating the 1988 massacre of Kurds, in which an estimated 5,000 people were killed by Sarin and VX gas in the Kurdish city of Halabja. It was his third death sentence since U.S.-led forces overthrew the Baath government of Saddam Hussein in 2003.
He received his first death sentence in 2008, though his execution was delayed because of disputes in the three-member presidency council in Baghdad.
Iraqi Prime Minister Nouri al-Maliki is expected to call for Majid's execution before the Iraqi people head to the polls to pick their next government in March, London's Telegraph newspaper reports.
The Kurdistan Regional Government in Iraq said it protested the crimes-against-humanity charge for Majid, saying the Halabja massacre should be labeled as an act of genocide.
Majid did not deny charges he ordered the attacks on the Kurds.
"I will kill them all with chemical weapons," he was heard on tape in 1988. "Who is going to say anything?"
The attack was ordered in the wake of the Iran-Iraq war in the 1980s. It is considered the worst chemical weapons attack on a civilian population in history.