Which Harry Potter novel has the longest title?

Harry Potter and the Order of the Phoenix has the longest title among J.K. Rowling’s seven Harry Potter novels.

The title refers to the Order of the Phoenix, a secret organization founded by Albus Dumbledore to oppose Lord Voldemort. The fifth novel was published in 2003 and is the longest book in the original series by word count in its English editions.

The story takes place during Harry’s fifth year at Hogwarts. It introduces or develops important elements including the Ministry of Magic’s refusal to accept Voldemort’s return, the oppressive Hogwarts teacher Dolores Umbridge, and Harry’s connection to the Order.

The title is sometimes misidentified as Harry Potter and the Deathly Hallows because that title contains the distinctive phrase “Deathly Hallows.” However, title length is determined by the full wording, and “Harry Potter and the Order of the Phoenix” contains the most words in the series.