In the scene where Harry, Ron, and Hermione are discussing Harry's kiss with Cho, the three begin to crack up near the end of the scene. This was all real laughter from the three actors. Director David Yates thought it was good for the scene, and kept rolling.
Daniel Radcliffe came up with the idea that, as a gesture of respect to a teacher that Harry most certainly looked up to, he would wear a certain type of clothes that resemble the outfit worn by Professor Lupin in his lessons from Harry Potter and the Prisoner of Azkaban (2004), during his teachings. David Yates liked the suggestion, so that became the basis for his look during those scenes.
Evanna Lynch beat 15,000 girls for the role of Luna. She was ninth in a line of 29 finalists, and when it came to viewing the audition videos, one of the producers, David Barron, stopped viewing after her audition, saying, "She is Luna." Unknown to them, Lynch actually wrote a letter directly to J.K. Rowling.
Since this film would include wand dueling at an elite level, a specific "wand choreographer" (Paul Harris, who is actually a professional dance choreographer) was brought in to design the style and technique of this highly unorthodox way of fighting. The result consists of five basic spell-casting moves, which each of the actors were then allowed to adapt slightly to fit their own character. So, for instance, Lucius Malfoy would have a very formal and somewhat 'stiff' fighting style, while Sirius Black uses a snappy and more spontaneous 'street fight' style.
According to the original script, the character of Kreacher was not intended to be in this film at all. But after J.K. Rowling read the script, she more or less insisted on him needing to be there to avoid some serious problems with future installments of the series. Though Kreacher has no noticeable impact on the plot or story as it's presented in the film, a couple of scenes with him were added at the last minute based on this request.
Dumbledore's line "Don't fight him, Harry, you can't win.", was featured prominently in just about every trailer and television spot, yet it is nowhere in the final version of the film, nor in the DVD's extended scenes.
Emma Watson was seriously thinking whether or not to keep acting in the film franchise after this installment, but decided to stay after considering that it would be uncomfortable to watch the films being made with someone else as Hermione.
During the breakfast scene in the Great Hall, boxes of cereal can be seen with the names Cheeri-Owls and Pixie-Puffs, with color schemes similar to those of Cheerios and Sugar Puffs boxes, respectively.
Several members of the Black family are named after astronomical objects. You can see some of the names in the scene when Sirius and Harry are in the family tree room. Sirius, Regulus, Andromeda, Arcturus, Bellatrix, and Cygnus are the ones that can be seen.
Katie Leung was nervous about kissing Daniel Radcliffe onscreen, and spent several weeks preparing herself for it. On the planned day for the shooting of the scene, Radcliffe came down with an illness, and filming had to be postponed while he recovered.
This film reveals several characters to be related to Sirius Black, most notably his cousin Bellatrix Lestrange, whose sister (Narcissa) is Draco Malfoy's mother. One connection that is not mentioned in this film is that Nymphadora Tonks is family as well (first cousin, once removed), as her mother (Andromeda) is sister to both Bellatrix Lestrange and Narcissa Malfoy. Andromeda's name can be seen on the tapestry in Sirius' house, but her portrait has been burned off; the book explains that her family disowned her for marrying a Muggle-born wizard. Tonks' name is also on the tapestry, but doesn't feature as prominently, so one has to really look for it.
Imelda Staunton was the producers' only choice for the role of Professor Dolores Umbridge. She and Jany Temime came up with the idea of making her dress more padded and more saturated as the film progresses. The novel describes her being physically chubby, and like a toad.
When they discover the Room of Requirement, Ron asks if it could become a bathroom if the user really needed it. This is a reference to the novel 'Harry Potter and the Goblet of Fire'. In it, the Room of Requirement is mentioned for the first time, having become a lavatory for Dumbledore.
During filming of the stand-off scene in the Ministry of Magic, Matthew Lewis suffered a perforated eardrum after accidentally moving his head while Helena Bonham Carter had her wand in his ear "..as a sort of Q-Tip...(to) sort of torture (his ear)" Carter said. Lewis was deaf in that ear for a few days afterward, though he laughed about the incident in interviews.
In Harry Potter and the Chamber of Secrets (2002), when Ron is rescuing Harry from the Dursley's, Ron tells Harry that they were "rescuing you, of course!". In this film, Moody says the same thing when he rescues Harry.
Although based on the longest book in the seven book series, this is the second shortest movie in the Harry Potter film franchise. The longest film, Harry Potter and the Chamber of Secrets (2002), is based on the second shortest book.
J.K. Rowling had been a schoolteacher before writing the Potter books, and this film features some references to the British educational system. In the late 1980s and early 1990s, students at age 16 were given Ordinary Level (O-Level) exams in all their major subjects, for which they can receive their General Certificate of Education. This corresponds to the Ordinary Wizarding Level (O.W.L.) exams given at Hogwarts. Students who planned to go on to university stayed on two more years to take their Advanced (A-Level) Exams, which roughly correspond to N.E.W.T. (Nastily Exhausting Wizarding Test) Exams.
The Department of Mysteries was the first completely computer-generated set used in the franchise. Building the set practically was too expensive, since an estimated 15,000 crystal balls would have been needed, and it would have taken a lot of time to clean, and set them up again between takes.
Kenneth Branagh was originally set to return as Professor Gilderoy Lockhart in a brief cameo. Originally, Harry was to encounter his former professor in an wizard hospital while visiting Ron's dad Arthur Weasley at St. Mungo's. The scene was meant to establish Lockhart as irrevocably scarred from his backfired curse in Harry Potter and the Chamber of Secrets (2002), as well as the insanity of Neville's parents after being tortured by Bellatrix Lestrange. The scene was cut for pacing and budget issues, as it would have necessitated building a new set.
Since Alastor Moody (Brendan Gleeson) has a prosthetic leg, he could not balance properly on broomstick, being unable to use the stirrups. Instead, his broom has posts at the front where he rests his legs, a seat which allows him to lean backwards, and a control stick for his hands. The arrangement is very similar to automobiles made for double-amputees, which have hand controls instead of pedals.
Over 30,000 individually placed tiles were used to create the Ministry of Magic sets. As real ceramic tiles would have been far too expensive to produce, they were instead made out of heavily-painted cardboard.
James Phelps and Oliver Phelps, who play Fred and George in the franchise, make a cameo appearance in the picture of the original Order of the Phoenix as their deceased uncles, Fabian and Gideon Prewett.
The Room of Requirement was described as a room with no beginning or end. To achieve the sense of infinity, the effects crew spent five months designing the room by having rotatable mirrors installed that would minimize camera and crew reflection as well as to avoid the Hall of Mirrors effect (a common term in CGI). Also, the lighting underneath the grille was quite bright to generate reflection, so the floor had to be in black, cast members had to have black velvet covering their shoe soles, while the crew had to wear surgical shoes to prevent treading dust onto the floor set.
Professor Dolores Umbridge, though she teaches in a classroom that has appeared in films two through four, inhabits an office vastly different from those of her predecessors. The set was redressed with "fluffy, pink filigree," including a carpet that cost 50,000 pounds to make, and several plates, upon which moving kittens were animated in post-production. A 24-hour photo shoot was held to photograph and film the kittens for use on these plates. Even the elegant quill, which Umbridge gives Harry to write lines, using his own blood, was designed by the set designers.
J.K. Rowling revealed that the character of Dolores Umbridge was based on a real person whom she "disliked intensely on sight", and who "returned (her) antipathy with interest", even though she honestly could not explain why they hated each other so much.
The portrait in Dumbledore's office that he addresses as "Phineas" is in fact Phineas Nigellus Black, great-grandfather of Sirius Black and, by extension, Bellatrix Lestrange and Narcissa Malfoy; as well as being great-great-grandfather to Draco Malfoy and Nymphadora Tonks.
The character of Grawp was done by using a recent breakthrough in film technology, developed by Image Metrics, which allows a computer to map an actor's performance onto any character virtual or human, living or dead. The result is said to be far superior to standard hand-drawn computer graphics which are very costly and time-consuming.
When Sirius joins Harry in the room with the Black family tree, to the lower left of the door is a Starbucks logo. The "siren" (a mermaid with two tails) has been stylized to be in keeping with the decor of the room, but she is wearing a crown and holding both her fins aloft like the Starbucks logo.
In the Atrium of the Ministry of Magic, many offices are seen layered upon each other. In reality, there are only two layers (floors), but at different times, different people were filmed doing different things in the offices, and later with the help of computer animation, put together to get the illusion of several layers of offices.
During the Premier of Harry Potter and the Order of the Phoenix, around twenty wooden and leather bound Hogwarts Crest journals were given to a select few competition winners, along with a gold tip fountain pen and inkwell, which comes boxed. On the box, it says Harry Potter and the Order of the Phoenix (s07) representing the year of its release. Inside the journal, the paper appears to be parchment paper with Harry Potter and the Order or the Phoenix water stamped on each page. The gold tipped fountain pen also had Harry Potter and the Order or the Phoenix stamped on it.
Rose Windsor, a member of the British Royal Family, worked - and is credited as - an Art Department Assistant on this film. Her wedding to a member of the Royal Family was featured in OK! magazine - largely due to Prince William's girlfriend Catherine Duchess of Cambridge attending her wedding. She specifically asked to be credited on Harry Potter as 'Rose Windsor' rather than her full Royal title.
The real reason behind why the dementors were in Little Whinging, is never really revealed in the film. The book provides the answer to this, Professor Dolores Umbridge sets them off, as she wanted (according to the book) Harry 'silenced', and acted upon Fudge's instructions, who was in denial of Voldemort's return.
The studio considered moving the entire production out to Barradov in Prague, from Leavesden, to take advantage of its incentives, but the move was vetoed by Alan Rickman and David Heyman, primarily on security issues.
Luna references a line from the original Peter Pan (1953). Wendy asks Peter "but Peter, how do we get to Neverland?" Peter responds "we fly of course!" In The Order of the Phoenix, Harry asks "how do we get to London?" Luna responds "we fly of course!"
The set of the Hall of Prophecies was entirely digitally built. During a fight scene which occurs there, prophecies crash to the ground and break; had it been an actual physical set, the reset time would have been several weeks.
Edgar Bones, the Wizard standing to the left of Dumbledore and directly behind James Potter and Sirius Black, was played by Cliff Lanning (wearing a false mustache), the 1st Assistant Director of the movie.
According to David Yates, he had originally shot a three-hour film. However, some material had to be cut out in the final edit, as the movie was 45 minutes too long. Therefore, several locations which were used for various scenes do not appear in the final cut of the film. In Virginia Water, scenes were shot where Professor McGonagall recovers from Stunning Spells, and Burnham Beeches was used for filming the scene where Hagrid introduces his fifth-year Care of Magical Creatures class to Thestrals. Harry skips stones in front of the Glenfinnan Monument in Glenfinnan in another cut scene.
Miles Jupp, famous for playing the role of Archie the Inventor, in the British children's show Balamory (2002), portrayed a television weatherman towards the start of the movie. The cameo only lasts six seconds.
David Yates believed he was approached to direct because the studio saw him fit to handle an "edgy and emotional" film with a "political backstory", which some of his previous television projects including State of Play (2003), Sex Traffic (2004) and The Girl in the Café (2005) demonstrated. David Heyman supported Yates' comments about the film's political theme, stating that "(Order of the Phoenix) is a political film, not with a capital P, but it's about teen rebellion and the abuse of power. David has made films in the UK about politics without being heavy handed." On the film's political and social aspects, Emma Watson stated that "somehow it talks about life after July 7th, the way people behave when they're scared, the way truth is often denied, and all the things our society has to face. Facing the fact that the authority is corrupted means having a non-conformist approach to reality and power."
Stuart Craig's design of The Ministry of Magic was inspired by early London Underground stations, where, he said, architects "tried to imitate classical architecture but they used ceramic tile", as well as a Burger King on Tottenham Court Road in London, where "there's a fantastic Victorian façade which just embodies the age".
Tiana Benjamin was scheduled to return for the film, in the role of Angelina Johnson, the Captain of the Gryffindor Quidditch team, but she had to withdraw, due to a commitment to playing Chelsea Fox in EastEnders (1985). The character, as well as the entire Quidditch subplot, was ultimately cut from the film. She did, however, record sound clips for the Order of the Phoenix video game.
Chris Columbus, the director of the first two Harry Potter films was amazed how beautifully Daniel Radcliffe, Emma Watson, and Rupert Grint matured over the series, compared to some child actors, who start out adorable, and then either lose that, or become bad actors as they grow older.
Caio Cesar, a prominent Brazilian voice actor, who dubbed Daniel Radcliffe as Harry Potter, and in other films, was also a military cop, and died at the age of 27 in 2015, after being shot in his neck, at the Complexo do Alemão slums, in Rio de Janeiro.
Warwick Davis: Because Warwick Davis has so little screen time in his usual Flitwick role, he was allowed to do an uncredited cameo as an unnamed Ministry personnel. He's the bald guy who joins Harry in the lift heading to the hearing.
In the original outline for the novel, the character of Arthur Weasley was to be killed off by Voldemort to entice Harry to the Department of Mysteries. J.K. Rowling couldn't go through with killing off such a beloved character, so Weasley was allowed to survive, albeit gravely injured. Interestingly, Arthur Weasley was again considered to be killed off in the final novel (later adapted as Harry Potter and the Deathly Hallows: Part 2 (2011)), but Rowling again changed her mind.
Many fans were critical of the scene where Harry sees Voldemort at the train station dressed in a Muggle suit, saying it was out of character for Voldemort to do such a thing. David Yates and David Heyman both defended the scene, though each had different takes on it. Yates explained that it was Voldemort's way of taunting Harry, that Voldemort could appear in plain sight, in a crowd of Muggles, who would not realize how dangerous he is. Heyman, on the other hand, said that it's a figment of Harry's imagination, symbolizing Voldemort taking control of Harry's mind.
When Dumbledore's Army first meets at the Hog's Head Inn, there is a bartender accompanied by a goat, played by Jim McManus, and credited as "Barman." This character is later identified as Aberforth Dumbledore, the Professor's younger brother. This character returns in Harry Potter and the Deathly Hallows: Part 2 (2011), and is played by Ciarán Hinds.
Though the Mirror of Erised doesn't appear in the novel, it turns up in the movie. It can be seen during Harry's possession by Voldemort and when Harry draws closer to the mirror his face is shown distorted with some of the Dark Lord's features. David Yates and Stuart Craig decided to use it as there as one more example of the many appeals to objects and shots from previous movies on the series.
Originally, the death of Sirius Black appeared just as it does in the novel, with Bellatrix hitting him in the chest with an unknown spell (but most likely a Stunning Spell), which causes him to stumble and fall through the death archway after a longer one-on-one duel. Though filmed, the sequence was cut due to time and pacing issues. A portion of this original death scene remains in the final film: when hit with the killing curse, Sirius seems to stagger, but then gets sucked in through the arch.
Although not addressed in the film, the voice from the orb making the prophecy belongs to Professor Sybil Trelawney (Emma Thompson). In the novel, Professor Dumbledore explains that Trelawney got into a state of trance during her job interview and made the original prophecy (although completely unaware of it herself). He a adds that Trelawney making such an important prediction was the only reason why Dumbledore hired the otherwise incompetent teacher in the first place.
Near the end of the movie, when Voldemort faces off with Dumbledore in duel, you can clearly see Dumbledore use The Elder Wand. The Elder Wand is the greatest wand ever made. The Elder Wand also is the vital element in the last installment, Harry Potter and the Deathly Hallows: Part 2 (2011). The Elder Wand was also clearly visible in the Prisoner of Azkaban, too.