Iraq's armed forces held a military parade in Baghdad on Sunday to celebrate the victory announced by Prime Minister Haider al-Abadi over ISIL.
Iraqi army units marched through the main square in central Baghdad as helicopters and fighter jets flew overhead.
Unlike Mr Abadi's victory announcement on Saturday, the parade was not broadcast live and only state media were allowed to attend.
Mr Abadi said Iraq had defeated the jihadists "through our unity and our determination" and declared Sunday a public holiday.
The ISIL extremists seized control of large parts of Iraq and neighbouring Syria in 2014, declaring a cross-border "caliphate" and committing widespread atrocities. At their height, the extremists threatened the country's very existence. With backing from a US-led coalition, Iraqi forces gradually retook control of all territory lost to ISIL over the last three years.
Lieutenant-General Paul E. Funk II, top commander of the US coalition sent his congratulations to the Iraqis and pledged continuing support.
"Much work remains, and we will continue to work by, with and through our Iraqi partners to ensure the enduring defeat of Daesh and prevent its ability to threaten civilisation, regionally and globally." Lt-Gen Funk said.
Iraqi forces captured the last ISIL strongholds in Iraq's western deserts on Saturday and secured the country's border with Syria. However, experts warn that ISIL remains a threat as an insurgent group capable of carrying out high-casualty bomb attacks using sleeper cells.