Steve Kloves

We want to write J.K. Rowling, J.K. Rowling, J.K. Rowling (because we basically worship the ground she walks on), but the facts are the facts: J.K. Rowling did not write this screenplay.

Instead, a dude named Steve Kloves not only wrote the screenplay for Harry Potter and the Sorcerer's Stone, but he actually penned almost the entire Harry Potter film franchise. (He missed the fifth one, presumably because eleven years on one series is a lot for one mere Muggle to take.)

He was a respected screenwriter for many years, with a pair of decidedly grown-up movies under his belt already: The Fabulous Baker Boys and Wonder Boys. Having cornered the market on movies ending with the word Boys, he moved on to Harry Potter, with the blessing of Warner Bros.

J.K. Rowling proved a much harder sell, and Harry's creator wasn't prepared to cut him much slack. He won her over when he said that his favorite character was Hermione…which she wasn't expecting at all. (We're Hagrid fans, ourselves.) (Source)

From then on, it was tons of hanging out around the laptop as Kloves gave it his all to make sure Rowling was happy with his work.

Apparently, blockbusters are to Kloves' liking. After finishing up with Harry and the gang, he went to work on another blockbuster franchise: The Amazing Spider-Man.