Iraqi TV said Jumaili was killed with other ISIS terrorists in a strike carried out by the Iraqi air force in the region of al-Qaim, near the border with Syria. It gave no detail or date for the raid.
"The air force's planes executed with accuracy a strike on the headquarters of Daesh in al-Qaim... resulting in the killing of Ayad al-Jumaili, alias Abu Yahya, the war minister," said state TV, citing a statement from the directorate of military intelligence.
Iraqi forces, backed by a US-led coalition, have been battling since October to retake the city of Mosul, ISIS' stronghold in Iraq and the city where Baghdadi declared a 'caliphate' nearly three years ago.
Tens of thousands of refugees have been fleeing the city to escape the fighting.
US and Iraqi officials believe Baghdadi has left operational commanders with diehard followers to fight the battle of Mosul, and is now hiding out in the desert with senior commanders.
A separate battle is in preparation in Syria to drive ISIS from its stronghold there, the city of Raqqa.
The Iraqi state TV report is the first by an official media to announce the death of Jumaili, who was an intelligence officer under Saddam Hussein, the Iraqi president toppled in the 2003 US-led invasion.
Jumaili led ISIS' top security agency in Iraq and Syria, known as Amniya, answering directly to Baghdadi, according to experts.