The revelation came as her answer to the question, which asked if Dumbledore had found "true love".
JK Rowling, 42, answered: "Dumbledore is gay," and she went on to explain that the headmaster had fancied his rival Gellert Grindelwald, who he had defeated in a battle between good and bad wizards in the past.
Fans and fan sites for the Harry Potter books and films have often debated Dumbledore's sexuality because it is known that he had a mysterious past that troubled him.
Gay rights activist Peter Tatchell is reported to have said: "It's good that children's literature includes the reality of gay people, since we exist in every society."
