The BBC has been airing the British science-fiction television series Doctor Who since 1963. It follows the exploits of a Time Lord named the Doctor, an extraterrestrial with a human-like appearance. The Doctor travels around space in the TARDIS, a time-traveling spacecraft that resembles a British police box, and encounters many people while doing so.

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Thus, many iconic actors have rounded out the cast with bit roles. Some stars only appear in one episode, and fans might quickly forget they ever had a guest role on the show. Here's a refresher for celebrities that fans of Doctor Who may forget.

James Corden

Two guys pushing a baby trolly in the mall

James Corden made two appearances in season 5, episode 11, “The Lodger,” and season 6, episode 12, “Closing Time,” as Craig Owens, the Doctor's honorary companion, in 2010 before going on to become a well-known TV host in America today. Along with his stint on Doctor Who, Corden has acted in several other projects, including Into the Woods, Cats, and, most recently, Cinderella.

Andrew Garfield

A bunch of guys look in awe as they see something

In addition to playing Spider-Man in The Amazing Spider-Man series and receiving an Academy Award nomination for his work in tick, tick...BOOM!, Andrew Garfield had two appearances in episodes of Doctor Who as Frank (season 3, episode 5, "Daleks in Manhattan" and episode 6, "Evolution of the Daleks"), a near victim of the Daleks who had a shaky Tennessee accent. The most recent films Garfield starred in are The Eyes of Tammy Faye, Spider-Man: No Way Home, and Under the Banner of Heaven as Detective Jeb Pyre.

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Carey Mulligan

Close up on a frightening girl

Sally Sparrow, played by Carey Mulligan, first appears in season 3, episode 11, "Blink," where the Weeping Angels are introduced to the viewers. Sally, a London-based photographer, unwittingly helped the Tenth Doctor during his encounter with the aforementioned antagonists. An Education, Drive, The Great Gatsby, and Promising Young Woman are among Mulligan's best-known roles.

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Felicity Jones

people in the 20s are scared

Felicity Jones is widely recognized for her performances as Jyn Urso in Rogue One and Jane Hawking, Stephen Hawking's wife, in The Theory of Everything, which earned her an Oscar nomination. But back in 2008, she appeared in a Doctor Who episode as Robina Redmond, a socialite from the 1920s with a secret (season 4, episode 8, "The Unicorn and the Wasp"). The Midnight Sky and The Last Letter From Your Love are two recent films starring Jones.

Joe Dempsie

A guy pointing a gun at the camera

Fans generally recognize Joe Dempsie as Gendry from Game of Thrones and Chris from Skins, but he is known to Doctor Who fans as Cline, a soldier who appeared in season 4, episode 7, "The Doctor's Daughter." Dempsie most recently appeared in Adult Material and Pieces of Her, in which he co-starred with Toni Collette.

Daniel Kaluuya

Three people chatting in a bus

Daniel Kaluuya is best known for his work on Jordan Peele’s critically acclaimed horror films, Get Out and Nope. However, he also participated in Doctor Who by playing Barclay in season 4, Episode 16, "Planet of the Dead," one of five special episodes aired between seasons 4 and 5. Other notable works by Kaluuya include Black Panther, Judas and the Black Messiah, and Queen and Slim.

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Maisie Williams

two girls in abnormal suits are trying to talk to someone

In addition to her role as Arya Stark from Game of Thrones, Maisie Williams also played Ashildr in four distinct episodes of Doctor Who's 9th season (“Hell Bent,” “Face the Raven,” “The Woman Who Lived,” and “The Girl Who Died”). Williams has appeared in several other projects alongside her iconic performances, including The Falling, The New Mutants, Two Weeks to Live, and most recently, Pistol.

Noma Dumezweni

A lady in military suit is speaking to someone

Noma Dumezweni made her debut as Captain Erisa Magambo of UNIT in a few Doctor Who episodes (season 4, episode 12, "Turn Left," and episode 16, "Planet of the Dead") before going down in history as the first Hermione Granger to appear on stage in Harry Potter and the Cursed Child. Demezweni’s other prominent acting roles include Made for Love, Frankie, and The Boy Who Harnessed the Wind.

Simon Pegg

Close up on a blonde creepy guy

By the time Simon Pegg made his Doctor Who debut as The Editor in season 1, episode 7, "The Long Game," he had already starred in several big-budget films, including Shaun of the Dead and Land of the Dead. Later, Pegg's portrayals as Benji in the Mission Impossible series and Gary King in The World's End became more well-known to viewers. Pegg most recently appeared in a near-future thriller television series, The Undeclared War.

Nick Frost

A guy is speaking to santa claus

Nick Frost, Simon Pegg's co-star in the Cornetto trilogy (Shaun of the Dead, Hot Fuzz, and The World's End), additionally played Santa Claus in Doctor Who, season 8, episode 12, "Death in Heaven" and the season 9 Christmas special, "Last Christmas." In addition, Frost is a well-known actor who appears in several television programs and motion pictures, such as Why Women Kill, Into the Badlands, and Fighting with My Family.

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Kylie Minogue

A couple posing for a party photo

In the Tenth Doctor's second Christmas special, "Voyage of the Damned," pop icon Kylie Minogue portrayed Astrid Peth, who may have been the shortest-lived partner in the show's history. Minogue is well recognized for her roles as The Green Fairy in Moulin Rouge! and Charlene Mitchell/Robinson in the television series Neighbours.

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Bill Nighy

Two guys talking at the museum

In season 5, episode 10, "Vincent and the Doctor," Bill Nighy made a little appearance as a contemporary Van Gogh specialist, but he was uncredited. Nighy is a well-known face in the film industry with many notable credits, including the role of Davy Jones in the Pirates of the Caribbean franchise, Love Actually, About Time, and Page Eight. He recently starred as Thomas Newton in a Showtime original series, The Man Who Fell to Earth.

Peter Kay

A guy being chased by a monster

Peter Kay, widely known for his work on Car Share and Phoenix Nights, also appeared on Doctor Who as Victor Kennedy in season 2, episode 11, "Love & Monsters." Kay has completed a couple of further projects, such as Cradle to Grave, Roary the Racing Car, and Max & Paddy's Road to Nowhere.

Michael Gambon

Two guys with the lanterns

Michael Gambon, best known for his role as Albus Dumbledore in the Harry Potter films, played Kazran Sardick, an Ebenezer Scrooge-like figure who presided over his planet's skies in the 44th century that made an appearance in the 2010 Doctor Who Christmas episode “A Christmas Carol.” Gambon also appeared in The Cook, the Thief, His Wife, & Her Lover, Johnny English Strikes Again, and most recently, Cordelia.

Sir Ian McKellen

An old guy with a snowball-like globe

Sir Ian McKellen technically did not appear in Doctor Who, although he did contribute his distinctive baritone voice to the 2012 holiday special "The Snowmen." The disembodied alien known as the Great Intelligence that controls the snow in Victorian London was voiced by the Lord of the Rings actor. McKellen has been seen in a sci-fi mystery, Infinitum: Subject Unknown.

Helen McCrory

A woman standing over a man

In 2010, the late actress Helen McCrory introduced her distinct boldness to Doctor Who, perhaps best known for her performances in Peaky Blinders, Penny Dreadful, and as Narcissa Malfoy in the Harry Potter films. McCrory played Rosanna Calvierri, the vampires' queen in season 5, episode 6, "The Vampires of Venice," who had a lavish fashion sense that was only matched by her cunning plans.

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