Which Harry Potter novel by J.K. Rowling was published on 21 June 2003?

Harry Potter and the Order of the Phoenix was published on 21 June 2003.

It is the fifth novel in J.K. Rowling’s seven-book Harry Potter series. The story follows Harry’s return to Hogwarts during a period when the Ministry of Magic refuses to accept that Lord Voldemort has returned.

The novel introduces the secret student group Dumbledore’s Army and the Ministry-appointed teacher Dolores Umbridge. It also develops the Order of the Phoenix, an organization resisting Voldemort that had existed during the earlier conflict with him.

The publication date is sometimes confused with the release dates of the film adaptation or neighboring novels. The book appeared in 2003; its film adaptation, Harry Potter and the Order of the Phoenix, was released in 2007.