Before Twilight turned Robert Pattinson into a global superstar, he appeared as Hogwarts student Cedric Diggory in Harry Potter and the Goblet of Fire. Cedric is one of the school's most talented students and represents Hogwarts in the famed Triwizard Tournament, where he unfortunately met a tragic fate at the hands of Voldemort. | © Warner Bros. Pictures
Jason Isaacs may be strongly associated with Lucius Malfoy now, but his appearance in the franchise can still be surprising when viewed alongside his other work. Isaacs had already built an impressive career through films such as The Patriot and Armageddon. Still, his sinister portrayal as Draco's father is one of his best acting performances, and it made him one of the series' most recognizable villains. | © Warner Bros. Pictures
Gary Oldman's appearance as Sirius Black is technically one of the biggest Harry Potter castings, but his extensive filmography makes it easy to forget just how many other iconic characters he has played. Black plays an integral role in Harry's journey, and his portrayal could not have been done any better by Oldman. Before joining the franchise, Oldman had portrayed figures such as Dracula and Sid Vicious, while later roles included Commissioner Gordon and Winston Churchill. | © Warner Bros. Pictures
David Thewlis brought considerable dramatic credibility to the role of Remus Lupin, Harry's compassionate Defense Against the Dark Arts teacher. Lupin was also a secret werewolf, which was quite the revelation in Harry Potter and the Prisoner of Azkaban. Thewlis had already appeared in critically acclaimed movies such as Naked and Seven Years in Tibet before joining the wizarding world. | © Warner Bros. Pictures
Brendan Gleeson had already established himself as a major character actor before taking on the role of Alastor "Mad-Eye" Moody. His rather gruff and slightly kind-hearted portrayal of the paranoid Auror made Moody instantly recognizable. He was also able to show a different side of the character in Harry Potter and the Goblet of Fire, which was quite impressive. | © Warner Bros. Pictures
Kenneth Branagh is one of the biggest names in British theater and cinema, yet he once played one of the Harry Potter franchise's most ridiculous characters. Branagh portrayed Gilderoy Lockhart, the rather vain Defense Against the Dark Arts professor in The Chamber of Secrets. He did a phenomenal job showcasing how extremely arrogant and self-obsessed Lockhart was. | © Warner Bros. Pictures
Emma Thompson is one of Britain's most celebrated actors, so her role as the eccentric Professor Sybill Trelawney can sometimes get lost among her many famous performances. Thompson appeared throughout the franchise as the Divination teacher, complete with enormous glasses, dramatic predictions, and interesting fashion choices. | © Warner Bros. Pictures
Domhnall Gleeson joined the Harry Potter cast as Bill Weasley, the eldest Weasley brother, beginning with Harry Potter and the Deathly Hallows – Part 1. Although Bill is an important part of the Weasley family, Gleeson's role is relatively small compared with his later blockbuster appearances. He went on to star in Ex Machina, About Time, The Revenant, and the Star Wars sequel trilogy. | © Warner Bros. Pictures
Warwick Davis is one of the franchise's most familiar supporting actors, but his involvement goes beyond simply playing Professor Flitwick. He also portrayed several characters across the series, including Griphook and an unnamed Gringotts bank teller. Outside Harry Potter, he is best known for roles in Star Wars, Willow, and Leprechaun. | © Warner Bros. Pictures
Long before the Harry Potter movies became a massive hit, John Cleese was one of Britain's biggest comedy stars as a member of Monty Python. He briefly appeared as Nearly Headless Nick in Harry Potter and the Sorcerer's Stone and Harry Potter and the Chamber of Secrets. Because the character is a ghost who only appears in relatively short scenes, it is easy to forget that one of the most famous British comedians of all time was a part of the wizarding franchise. | © Warner Bros. Pictures
David Tennant had a memorable but relatively brief appearance as Barty Crouch Jr. in Harry Potter and the Goblet of Fire. The character spends much of the movie disguised as Mad-Eye Moody before his true identity is revealed. Crouch Jr. is a loyal and unhinged follower of Lord Voldemort. Today, Tennant is best known as the tenth Doctor in Doctor Who and for roles in Broadchurch and Good Omens. | © Warner Bros. Pictures
Bill Nighy had a relatively brief role as Rufus Scrimgeour, a powerful official in the Ministry of Magic who later becomes Minister for Magic after Cornelius Fudge. Because Scrimgeour only appears prominently in a handful of scenes, his casting is easy to miss. Before this role, Nighy was already famous for roles in Love Actually, Pirates of the Caribbean, and Underworld. | © Warner Bros. Pictures
Verne Troyer is arguably best known for playing Mini-Me in the Austin Powers movies, but he also had a small role in the first Harry Potter film. Troyer played the part of Griphook, the goblin who introduces Harry to the wizarding world's banking system. You'd be forgiven if you didn't notice him because he wore heavy prosthetics. Warwick Davis later took over the role in later films. | © Warner Bros. Pictures
Jamie Campbell Bower briefly played the young Gellert Grindelwald in Harry Potter and the Deathly Hallows – Part 1. Although his appearance is short, Grindelwald's past connection to Albus Dumbledore becomes an important part of the story. Bower later returned to the wizarding world in the Fantastic Beasts films, where he reprised the role as the younger version of the dark wizard. | © Warner Bros. Pictures
Way before Bridgerton made him a household name, Regé-Jean Page had a tiny, uncredited appearance in Harry Potter and the Deathly Hallows – Part 1. He can briefly be spotted as a wizard at Bill and Fleur's wedding, which, naturally, made him incredibly easy to miss. Considering Page would later become one of the biggest breakout stars in recent times, his rather short Harry Potter appearance is a fun piece of trivia. | © Warner Bros. Pictures
The Harry Potter cast was packed with famous faces, but some of its biggest stars were surprisingly easy to overlook. With that in mind, let's take a look at 15 actors and actresses you may have forgotten — or didn't even know — were part of the wizarding world.
