Scoring any type of role in the Harry Potter film franchise is a feat that is accompanied by some well-deserved bragging rights. The films were primarily shot in the United Kingdom, meaning that it was only really British citizens who had the chance of obtaining a cameo in any of the films.
There are a bevy of characters from the books that were in need of representation, and while some fans may have noticed the absence of some characters, a great portion of them made their way into the film. However, character arcs and backstories had to be cut because J.K. Rowling's wizarding world could not be told in full on the big screen. So while these actors were able to land cameos in this multi-million dollar franchise, you may not have understood their role at all.
Scarlett Byrne- Pansy Parkinson
Pansy Parkinson makes her way into the film series in Harry Potter and the Prisoner of Azkaban. She had always been a background character in the book but became more widely represented when she started dating Draco Malfoy.
However, it wasn't until Harry Potter and the Half-Blood Prince that Scarlette Byrne landed the staple role of Pansy Parkinson. Byrne is an English actress who only had one acting credit before her cameo in the Harry Potter films. Since then, she has continued acting mostly in television roles. Her most notable T.V. credit is for her role as Nora Hildegard in The Vampire Diaries.
Julie Christie- Madam Rosmerta
Madam Rosmerta is the landlady for The Three Broomsticks: a pub in Hogsmeade. In Harry Potter and the Prisoner of Azkaban, viewers meet her for the first time as she is portrayed by Julie Christie. In the scene, Madam Rosmerta speaks with Cornelius Fudge and Professor McGonagall about Sirius Black's history with the Potters. It is during this scene that Harry finds out that Sirius presumably betrayed his parents and that Sirius is his godfather.
The legend that is Julie Christie made it so that her cameo in the film would be a noticeable one. Christie is known for her iconic leads in films such as Doctor Zhivago and Farenheight 451. And although she only appeared on the screen for a few minutes, having the role of Madam Rosmerta isn't a bad mark to add to her resume.
Verne Troyer- Griphook
Griphook is the goblin that audiences see as vastly in charge at Gringotts Bank in Diagon Alley. This is the first character, apart from Hagrid, that Harry meets in Harry Potter and the Sorcerer's Stone. The daunting line "And does Mr. Potter have his key?" was spoken by none other than Verne Troyer.
Troyer only made a cameo appearance int he first Harry Potter installment before the role of Griphook was attached to Warwick Davis. Troyer is known for playing Mini-Me alongside Mike Myers in the Austin Powers films. Sadly, Troyer passed away in April of 2018 from alcohol poisoning.
John Cleese- Nearly Headless Nick
Nearly Headless Nick is a character that was sorely missed in the Harry Potter film franchise after producers decided to ax the character after the second film. Nicholas de Mimsy-Porpington is the official ghost of Gryffindor house whose nearly headless anecdotes are told time and time again to anyone willing to listen. He makes a steady appearance throughout the books, with an entire chapter devoted to Harry, Ron, and Hermione joining him at his 500th Death Day party.
Acclaimed actor, John Cleese makes a transparent cameo as the ghost in the first two films. In the second, the event that leads Nick to be petrified is a pivotal turning point in the film. Cleese is known for being the co-founder of Monty Python sketch comedy group and for blockbuster films such as A Fish Called Wanda.
Frank Dillane- Young Tom Riddle
Sixteen-year-old Tom Riddle is just as malicious and intimidating as he is when he becomes Lord Voldemort. In Harry Potter and the Half-Blood Prince, audiences learn of young Tom Riddle's history. The conniving Hogwarts student is even able to extract the secrets of making a Horcrux by the formidable Professor Slughorn in his early years.
This actor who makes this cameo appearance may look familiar. Frank Dillane was about eighteen years old when he played the part of young Tom Riddle. He is now better recognized as Nick Clark who he acts as a mainstay in AMC'S Fear the Walking Dead.
Freddie Stroma- Cormac McLaggen
In the films, Cormac McLaggen acts as the rival to Ron Weasley. Not only is he gunning for the Keeper spot on the Gryffindor Quidditch team, but he also develops a thing for Hermione. Cormac serves primarily as comic relief in Harry Potter and the Half-Blood Prince, although the core of his character is an egocentric jock.
The charming actor who plays the part of Cormac so well is an actor by the name of Freddie Strona. Stroma has made cameos in a number of successful films including his role as Luke in Pitch Perfect and his portrayal of Brit Vayner in 13 Hours alongside John Krasinski. Besides this Harry Potter cameo, Stroma has appeared in one other fantasy-based series that you may have heard of. In 2016, he appeared as Dickon Tarly in Game of Thrones.
Phil Selway- Drummer in the Yule Ball
The Yule Ball in Harry Potter and the Goblet of Fire showcases an eloquent (albeit, awkward) dance scene between the Hogwarts, Durmstrand, and Beauxbaton students. This is roughly transitioned to a mosh-pit scene where the students are thrashing along with The Weird Sisters: a rock band from the wizarding world.
The Weird Sisters are on screen for only a matter of seconds, but viewers with a keen eye were able to spot one unexpected cameo. Phil Selway is briefly seen in the dark corner of the screen as the drummer in the band, Orsino Thruston, His cameo was, no doubt, secured as a result of his real-life experience as a drummer for the famous rock group, Radiohead. He was joined on stage by Jarvis Cocker, Jonny Greenwood, and Jason Buckle who make up the remaining members of The Weird Sisters.
Michelle Fairley- Hemione's Mother
Before abandoning her education to help her friend Harry recover Voldemort's Horcruxes, Hermione is forced to do something heartbreaking. At the beginning of Harry Potter and the Deathly Hallows Part One, Hermione sneaks up behind her parents and performs the Memory Charm on them. She does this in order to make her parents forget they had a daughter so that she can protect them against the wrath of Voldemort's followers.
Audiences only get to catch a brief glimpse of Hermione's parents, but the cameo is unmistakable. Michelle Fairly plays the role of Hermione's mother. Audiences now know her as the actress who played Catelyn Stark in Game of Thrones.
Jamie Campbell Bower- Young Grindelwald
Before his story was told in Fantastic Beasts and Where to Find Them, Gellert Grindelwald was mentioned in Harry Potter and the Deathly Hallows Part Two. As Harry learns of Dumbledore's past and his malevolent ideas of purifying the wizarding world, Grindelwald comes into the picture as the true villain.
A young Grindelwald is only shown alongside Dumbledore in a brief snippet, but audiences recognized this cameo as Jamie Campbell Bower. Bower's acting credits are most associated with his roles in Sweeny Todd and the Twilight saga where he plays Anthony and Caius, respectively.
Luke Youngblood- Lee Jordan
Lee Jordon is a prominent character in the books, but his cameo in the Harry Potter films is sadly terse. He is the best friend of Fred and George Weasley and the animated commentator for every Hogwarts Quidditch match. Lee Jordan only appears in the first two Harry Potter movies and it played by actor Luke Youngblood. The actor was only a child when he landed the part of Lee Jordan, so his acting gigs are more recognized by his part in NBC's television series, Community, where he portrays the character Magnitude.