Eight feature films adapted J.K. Rowling’s original Harry Potter novels. Warner Bros. released the films between 2001 and 2011, beginning with Harry Potter and the Philosopher’s Stone and ending with Harry Potter and the Deathly Hallows – Part 2.
There are eight films because the seven-novel series received two adaptations of its final book. Harry Potter and the Deathly Hallows was filmed and released as Part 1 and Part 2, allowing the lengthy conclusion to receive more screen time.
The film total does not include the later Fantastic Beasts films, which are set in the same wider Wizarding World but are not adaptations of the original Harry Potter novels. It also does not count stage productions or television projects. That distinction explains why “seven books” and “eight films” are both correct but answer different questions.