Which film did J.K. Rowling write the screenplay for first?

Fantastic Beasts and Where to Find Them was the first film for which J.K. Rowling wrote the screenplay.

Released in 2016, the film was inspired by Rowling’s 2001 Hogwarts textbook tie-in of the same name. The screenplay expanded the brief fictional textbook into an original story centered on Newt Scamander, a magizoologist whose magical creatures escape in 1920s New York.

The film began a separate film series set in the wider wizarding world, decades before Harry Potter’s school years. Eddie Redmayne played Newt Scamander, while the story introduced American magical institutions and characters that had not appeared in the original novels.

Rowling did not write the screenplays for the eight Harry Potter films. Those adaptations were scripted by Steve Kloves, except that Rowling wrote the screenplay for the later Fantastic Beasts project. The film’s title is also sometimes shortened in casual references, but the full title is the canonical answer.