Which Harry Potter book is the longest by English-language word count?

Harry Potter and the Order of the Phoenix is the longest Harry Potter novel by English-language word count. The 2003 book contains roughly 257,000 words, making it the fifth and largest volume in the series.

The novel follows Harry’s fifth year at Hogwarts and introduces the oppressive Ministry-appointed teacher Dolores Umbridge. It also develops the secret student group Dumbledore’s Army and culminates in a battle at the Department of Mysteries.

Readers sometimes assume the finale, Harry Potter and the Deathly Hallows, is longest because it resolves the central conflict. Deathly Hallows is substantial, but Order of the Phoenix has the greater word count in standard English editions.

Page totals vary by font, edition and formatting, so word count is the more useful comparison.