[4] The series was mainly produced by David Heyman, and stars Daniel Radcliffe, Rupert Grint, and Emma Watson as the three leading characters: Harry Potter, Ron Weasley, and Hermione Granger.

The book, Harry Potter and the Philosopher's Stone, was relegated to a low-priority bookshelf, where it was discovered by a secretary who read it and gave it to Heyman with a positive review.

"[15] In the "Rubbish Bin" section of her website, Rowling maintains that she had no role in choosing directors for the films, writing "Anyone who thinks I could (or would) have 'veto-ed' him [Spielberg] needs their Quick-Quotes Quill serviced.

"[16] After Spielberg left, conversations began with other directors, including Chris Columbus, Jonathan Demme, Terry Gilliam, Mike Newell, Alan Parker, Wolfgang Petersen, Rob Reiner, Tim Robbins, Brad Silberling, and Peter Weir.

[23] Warner Bros. had initially planned to release the first film over the 4 July 2001 weekend, making for such a short production window that several of the originally proposed directors had withdrawn themselves from contention.

[10][26] Also in 2000, the then-unknown British actors Emma Watson and Rupert Grint were selected from thousands of auditioning children to play the roles of Hermione Granger and Ron Weasley, respectively.

[27] Los Angeles Times writer Geoff Boucher, who conducted the above-mentioned interview with Heyman, added that the casting of the three major roles "is especially impressive in hindsight.

[30] Tim Burke, the visual effects supervisor of the series, said of the production on Harry Potter, "It was this huge family; I think there were over 700 people working at Leavesden, an industry in itself."

Columbus said his vision for the first two films was of a "golden storybook, an old-fashioned look", while Cuarón changed the visual tone of the series, desaturated the colour palette, and expanded the landscape around Hogwarts.

Heyman also said that Kloves was the "key voice" in the process of adapting the novels and that certain aspects from the books needed to have been excluded from the scripts due to the filmmakers' decision to keep the main focus on Harry's journey as a character, which would ultimately give the films a defined structure.

Heyman mentioned that some fans "don't necessarily understand the adaptation process" and that the filmmakers would have loved to "have everything" from the books in the films but noted that it was not possible since they had "neither time nor cinematic structure" to do so.

"[45] Aside from the three lead actors, other notable cast members include Robbie Coltrane as Rubeus Hagrid, Tom Felton as Draco Malfoy, Alan Rickman as Severus Snape, and Dame Maggie Smith as Minerva McGonagall.

Notable recurring cast members include Helena Bonham Carter as Bellatrix Lestrange, Warwick Davis as Filius Flitwick, Ralph Fiennes as Lord Voldemort, Brendan Gleeson as Alastor Moody, Richard Griffiths as Vernon Dursley, Jason Isaacs as Lucius Malfoy, Harry Melling as Dudley Dursley, Gary Oldman as Sirius Black, Fiona Shaw as Petunia Dursley, Timothy Spall as Peter Pettigrew, David Thewlis as Remus Lupin, Emma Thompson as Sybill Trelawney, Mark Williams as Arthur Weasley, and Julie Walters as Molly Weasley.

Assisted by Stephenie McMillan, Craig has created iconic sets pieces including the Ministry of Magic, the Chamber of Secrets, Malfoy Manor, and the layout for the CGI Horcrux Cave.

I would take my roughs and plans and sections and give them to a professional architectural illustrator, who would create concept art using pencil and colour wash on watercolour paper."

[49] Six directors of photography worked on the series: John Seale on the first film, Roger Pratt on the second and fourth, Michael Seresin on the third, Sławomir Idziak on the fifth, Bruno Delbonnel on the sixth, and Eduardo Serra on the seventh and eighth.

[65] Yates stated that he wanted Williams to return to the series for the final instalment, but their schedules did not align due to the urgent demand for a rough cut of the film.

[66] The final recording sessions for Harry Potter took place on 27 May 2011 at Abbey Road Studios with the London Symphony Orchestra, Desplat and orchestrator Conrad Pope.

[71] Exactly four years earlier on that day, Rowling's official website revealed the title of the final novel in the book series – Harry Potter and the Deathly Hallows.

Harry is also beset by disturbing and realistic nightmares, while Professor Umbridge, a representative of Minister for Magic Cornelius Fudge, is the new Defence Against the Dark Arts teacher.

After unexpected events at the end of the previous year, Harry, Ron, and Hermione are entrusted with a quest to find and destroy Lord Voldemort's secret to immortality – the Horcruxes.

[73] The sixth, Harry Potter and the Half-Blood Prince, was released on 15 July 2009 to critical acclaim and finished its theatrical run ranked as the number two grossing film of 2009 on the worldwide charts.

[80] Much of the original cast and crew reunited for an HBO Max retrospective special titled Harry Potter 20th Anniversary: Return to Hogwarts, which was released on 1 January 2022.

Philosopher's Stone was the highest-grossing Harry Potter film up until the release of the final instalment of the series, Deathly Hallows Part 2, while Prisoner of Azkaban grossed the least.

[86][87][88] All the films have been a success financially and critically, making the franchise one of the major Hollywood "tent-poles" akin to James Bond, Star Wars, Indiana Jones and Pirates of the Caribbean.

The collective wizardry of an epic ensemble gave us the gift of growing older with Harry, Ron and Hermione as the magic of Hogwarts sprung from the films and into the hearts and minds of Muggles around the world.

[116][117] An observer noted that "cinematically, the Potter franchise-starter was marked by its commercial caution: its imagination was safely limited, its storytelling by-the-book in all senses, its budget spent to yield more value than magic" in contrast with how "Fellowship of the Ring, by comparison, was a reckless, wondrous extravagance".

[126] Half-Blood Prince was nominated for BAFTA Awards in Production Design and Visual Effects,[127] and it was in the longlists for several other categories, including Best Supporting Actor for Alan Rickman.

[132] Chris Columbus's Philosopher's Stone became the highest-grossing Harry Potter film worldwide upon completing its theatrical run in 2002, but it was eventually topped by David Yates's Deathly Hallows – Part 2, while Alfonso Cuarón's Prisoner of Azkaban grossed the least.

Costance Grady and Aja Romano, commenting on the whole Harry Potter franchise's legacy for Vox in light of its 20th anniversary, wrote that youth-targeted literature has since become "a go-to well of ideas for Hollywood", pointing to the successes of The Twilight Saga and The Hunger Games.