None of the Harry Potter films was directed by anyone outside Chris Columbus, Alfonso Cuarón, Mike Newell, or David Yates.
Chris Columbus directed the first two films, Harry Potter and the Philosopher’s Stone and Harry Potter and the Chamber of Secrets. Alfonso Cuarón directed Harry Potter and the Prisoner of Azkaban, while Mike Newell directed Harry Potter and the Goblet of Fire.
David Yates directed the final four films: Order of the Phoenix, Half-Blood Prince, and both parts of Deathly Hallows. Thus the eight-film series has four directors, with Yates handling the largest consecutive portion.
The question is designed around the complete film series rather than Rowling’s novels. Rowling wrote the books, but film directors shaped their screen adaptations under the production of Warner Bros.