The militant group published an obituaryin its online propaganda magazine 'Dabiq' for the terrorist, whose real name was Mohammed Emwazi but went by the name Abu Muharib al-Muhajir.
Emwazi, 27, was known as the executioner of the IS appearing masked in a string of videos showing the beheadings of Western hostages.
The US military had said it was "reasonably certain" it had killed Emwazi in the IS-stronghold of Raqqa.
At the time of his reported death in November, Prime Minister David Cameron said targeting Emwazi had been "the right thing to do".
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Kuwait-born Emwazi had appeared in beheading videos of victims including UK aid worker David Haines and taxi driver Alan Henning.
The article lists Emwazi's participation in various IS military conquests and praises his work.
"His harshness towards the kafir was manifested through deeds that enraged all the nations, religions, and factions of kafir, the entire world bearing witness to this," the author writes.
The publication also claims that Emwazi was known for his "mercy, kindness, and generosity towards the believers, his protective jealousy for Islam and its people, and his affection towards the orphans".
He later appeared in videos of the beheadings of US journalist Steven Sotloff, British aid workers David Haines and Alan Henning, and in November 2014, that of American aid worker Peter Kassig.
The 'Dabiq' article describes how Emwazi was able to sneak out of Britain, "Right under the nose of the much-overrated MI5 British intelligence agency, Abu Muharib together with his companion in hijrah carefully and secretly made their departure, utilising every means available to them".