What is the title of the eighth Harry Potter story, co-created by J.K. Rowling and first staged in 2016?

The eighth Harry Potter story, co-created by J.K. Rowling and first staged in 2016, is Harry Potter and the Cursed Child.

The work is a stage play written by Jack Thorne, based on an original story by Thorne, Rowling, and John Tiffany. Its plot begins nineteen years after the events of Harry Potter and the Deathly Hallows and follows Harry as an adult employee of the Ministry of Magic. His son Albus Severus Potter becomes central to the story.

The original West End production opened at the Palace Theatre in London in 2016. The published script was also released in 2016 and was marketed as the eighth official Harry Potter story.

Cursed Child is not an eighth novel written by Rowling. It is a play script, and its format and credited authorship distinguish it from the seven main novels.