It was released on 15 November 2002 in the United Kingdom and North America. The film was very well received at the box office, making US$879 million worldwide and is the 34th highest-grossing film of all time and the seventh highest-grossing film in the Harry Potter series. It was nominated for three BAFTA Film Awards in 2003.

Gilderoy Lockhart is a histrionic wizarding celebrity who has written many books on his exciting adventures encountering dark creatures. In Chamber of Secrets, Lockhart is appointed as Hogwarts's new Defence Against the Dark Arts instructor. He is unpopular with most of the staff, particularly Professor Snape. However, he is greatly admired by many others, particularly witches (including Hermione Granger and Mrs. Weasley), who find him attractive. Harry dislikes Lockhart for a number of reasons: his arrogance, his belief that Harry flew to Hogwarts in a car to seek further attention, his penchant for handing out signed photos of himself, and the trouble he has with simple magic such as healing Harry's broken arm (he accidentally removes all of Harry's arm bones instead). Lockhart is exposed as a charlatan and a coward when he attempts to avoid entering the Chamber of Secrets by revealing to Harry and Ron Weasley that he never performed the amazing feats documented in his books, instead stealing other wizards' experiences and erasing their memories. His attempt to use a Memory Charm on Harry and Ron backfires due to him using Ron's broken wand, and he suffers permanent near-total amnesia as a result.

In Order of the Phoenix, Harry comes across Lockhart in St Mungo's while visiting Mr. Weasley at Christmas. Lockhart is childishly proud of being able to write in "joined-up letters". He still enjoys signing autographs and still receives fan mail, although he has no idea why. For his part, Harry feels a slight twinge of guilt for Lockhart's amnesia, but he consoles himself with the fact that it was Lockhart's own fault. Lockhart never fully recovers, despite all efforts to cure him, and remains in St. Mungo's with amnesia. Harry and Ron never reveal that Lockhart was a fraud.

Rowling has said Lockhart is the only character she has ever based on a real-life person. Lockhart was inspired by an unrevealed acquaintance who was "even more objectionable than his fictional counterpart" and "used to tell whopping great fibs about his past life, all of them designed to demonstrate what a wonderful, brave and brilliant person he was."

Kenneth Branagh portrayed Lockhart in the film version of Chamber of Secrets. In a scene after the end credits, his latest book is on sale in Diagon Alley; entitled Who Am I?, it displays a picture of him humming distractedly to himself and wearing a straitjacket.

Also, on Pottermore, it was revealed that Lockhart had been in Ravenclaw house during his time as a student at Hogwarts, since he was not brave, but actually cunning and smart, but lacking skills in magic.