Igor Karkaroff is a fictional character in the Harry Potter series.

Karkaroff is a former Death Eater. He was captured by Auror Alastor Moody after the fall of Lord Voldemort; the Ministry of Magic released him from Azkaban in exchange for the names of other Death Eaters. He managed to injure Moody by ripping out part of his nose.

Karkaroff went on to become Head Teacher at Durmstrang Institute, a school of magic believed to be located somewhere in northern Europe. During his time there, actual Dark Arts are said to have been studied by the students of Durmstrang (instead of just defense against them). Moreover Durmstrang was only open to pure-blooded wizards and witches. It is not known how much of this was Karkaroff's direct influence to Durmstrang and how much preexisted his tenure.

Karkaroff was seen to show exceptional favouritism towards Bulgarian student Viktor Krum, champion of the 1994 Quidditch World Cup.

In 1994 Durmstrang entered the newly-revived Triwizard Tournament with Hogwarts School of Witchcraft and Wizardry and Beauxbatons Academy of Magic; as headmaster, Karkaroff was a Triwizard judge. After the unexpected inclusion of a second Hogwarts champion, Karkaroff threatened to drop out of the Tournament.

However, during the course of the year he met fellow ex-Death Eater Severus Snape, with whom he shared several conversations regarding past events.

In June 1995, at the end of the Triwizard Tournament, Karkaroff went into hiding after sensing the summons of Lord Voldemort. He has not been seen since that time, but Voldemort has made a comment to the point of making Karkaroff pay for his cowardice.

Igor Karkaroff's nationality is uncertain. Though he speaks without a foreign accent, his name would not suggest that he is of English descent.