Which Harry Potter novel did J.K. Rowling complete last in the main seven-book series?

J.K. Rowling completed the main seven-book series with Harry Potter and the Deathly Hallows.

The novel was published in 2007 and concludes Harry’s conflict with Lord Voldemort. Its plot follows Harry, Ron Weasley, and Hermione Granger as they search for Horcruxes while the wizarding world is controlled by Voldemort’s forces.

Deathly Hallows is the seventh and final novel in the original sequence. It is distinct from Harry Potter and the Cursed Child, a later stage play whose published script was credited to Rowling, Jack Thorne, and John Tiffany.

The title refers to three legendary magical objects: the Elder Wand, the Resurrection Stone, and the Cloak of Invisibility. These objects are introduced through the story of the Three Brothers.