It occurs at the end of an offensive launched on 17 October by the iraqi forces, supported by the global coalition led by the United States.
Troops from Iraqi Special Forces marked the victory by planting the Iraqi flag on the bank of the Tigris River. Iraqi forces are backed by air strikes and advisers of the US-led coalition fighting IS in Iraq and Syria since 2014.
Iraqi commanders said the militants were fighting for every scrap of territory, using snipers, grenades and suicide bombers. Heroes of the Emergency Rapid Division are celebrating the accomplishment of their mission and, God willing, Iraqi men, women and children will return safe to their homes.
The United Nations predicts it will cost more than $1 billion to fix basic infrastructure in Mosul.
Iraqi forces have been battling the remaining pockets of jihadists desperately holding out in a tiny area near the Old City.
"Mosul liberated from Daesh [IS' Arabic acronym]".
"We are seeing now the last meters and then final victory will be announced", Iraq's state TV reported on Saturday.
ISIS fighters sometimes charge improbable rates for necessities, such as the equivalent of $6 for a bottle of water and $80 for a package of crackers, an escapee from the city told ABC News last week.
USA -backed Syrian forces have pushed into the group's de facto capital, the northern Syrian city of Raqqa, but a final victory there could be months away, and the extremists still hold several smaller towns and villages across Iraq and Syria. Iraqi state TV says government forces have driven the militants from all areas and are "chasing" them in some areas in the city. The government does not reveal casualty figures, but a funding request from the US Department of Defense showed that the Counter Terrorism Service, which has spearheaded the fight in Mosul, had suffered 40 percent losses.
With Mosul, a city that had a population of around two million three years ago, the "caliphate" loses one of the main hubs of its administration and IS one of the most potent symbols of its might.