J.K. Rowling’s Harry Potter and the Order of the Phoenix was published worldwide on 21 June 2003.
The fifth Harry Potter novel appeared simultaneously in several major English-language markets on 21 June 2003. This coordinated launch was a major publishing event, reflecting the series’ enormous international readership and the effort to reduce unauthorized early sales or leaked plot details.
Order of the Phoenix is the longest novel in the original series by word count in its English editions. It follows Harry’s fifth year at Hogwarts, the Ministry of Magic’s refusal to accept the return of Voldemort, and the arrival of Dolores Umbridge as a powerful school authority.
The date is often confused with the publication dates of the other final-period books. Half-Blood Prince appeared in 2005, while Deathly Hallows appeared in 2007. The first book was published in 1997, making the 2003 release a midpoint milestone in the seven-book sequence.