▲Tom Cruise is a formidable actor who’s known around the world. However, he was substituted as Jack Reacher.

▲'Jack Reacher' is a book series authored by Lee Child. It had already been adapted as a film series, but Child decided to swap out Cruise for Jeff Bosley, in the 2019 release.

▲But Don Cheadle replaced Howard in the series, starting with 'Iron Man 2' in 2010.

▲Spacey was the original lead in 'All the Money in the World,' a biographical drama based on the kidnapping of John Paul Getty III in 1973.

▲However, she was replaced by Daphne Reid in 1993. In 2011, Hubert told TMZ that she'd "never do anything with [..] Will Smith." But in September 2020, ahead of a special reunion, the two reconciled.

▲Howard lit up the screen in 'Iron Man,' playing the superhero James Rhodes (War Machine).

▲However, after Spacey was hit with assault allegations, he was replaced with Christopher Plummer.

▲In 'True Blood' season six, Luke Grimes played James Kent.

▲Janet Hubert is best known for playing Vivian Banks in 'The Fresh Prince of Bel-Air,' from seasons one through three.

▲In season seven, Grimes was swapped out for Nathan Parsons.

▲For the first two 'Twilight' films, the character of Victoria was played by Rachelle Lefevre.

▲In season two, Ian Whyte (left) stepped in to play The Mountain. For season three, Hafþór Júlíus Björnsson (right) was cast, and played the character ever since.

▲Instead, Maggie Gyllenhaal was cast as Dawes. Holmes told MTV she "had a great experience working with Chris Nolan," but chose to star in 'Mad Money' instead.

▲Shannen Doherty (center) starred as Prue Halliwell in 'Charmed,' from season one to season three.

▲Edward Norton stepped in for 'The Incredible Hulk' in 2008. Then he was replaced by Mark Ruffalo in 'The Avengers,' which came out in 2012.

▲Unfortunately, Harris passed away in 2002. As a result, Michael Gambon replaced him as the headmaster of Hogwarts.

▲The Incredible Hulk has been played by many actors. From 2003 to 2012, the superhero was played by three actors, starting with Eric Bana in 'Hulk.'

▲In 'The O.C.,' the character of Kaitlin Cooper was originally played by a young Shailene Woodley.

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After Woodley went off to boarding school, Willa Holland was cast as her replacement for season three.

▲Doherty (center) wasn’t just replaced in 'Charmed.' She was once the star of 'Beverly Hills, 90210,' playing the cunning Brenda Walsh.

▲For 'Eclipse,' the actress was replaced by Bryce Dallas Howard. Lefevre said she was "stunned" to learn she was replaced, and that she was "fully committed to the 'Twilight' saga.”

▲"There was too much drama on the set and not enough passion for the work," Doherty said. She left the show after season three, and Rose McGowan (left) stepped in to play the character’s estranged sister.

▲Doherty left after four seasons, and Tiffani Thiessen stepped in as Valerie Malone, effectively replacing Doherty’s character.

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Johnny Depp lost out on his role as Grindelwald in the 'Fantastic Beasts' film series after he "was asked by Warner Bros to withdraw from the role after he came out on the losing end of an ugly legal battle he waged against a British tabloid for libeling him in describing him as a 'wife beater' in articles that covered his tempestuous marriage," reported Deadline. Warner Bros. announced that Mads Mikkelsen of 'Hannibal' fame would step into the role.

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After exiting the action-comedy 'Shotgun Wedding' starring Jennifer Lopez, Hammer was replaced by 'Transformers' star Josh Duhamel as leading man.

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Armie Hammer's entire slate of work was dropped in 2021 following a social media scandal. The controversy entailed some graphic messages he allegedly sent out, accusations of assault, and questionable cannibalism fantasies. The actor has called these "bulls—t claims," but nonetheless stepped away from his roles. That included Paramount+'s limited series 'The Offer,' in which Hammer was supposed to star as 'The Godfather' producer Al Ruddy. Instead, 'Whiplash' star Miles Teller took his place in the story, which is based on the Oscar-winning producer Ruddy’s untold experiences of making the iconic 1972 film directed by Francis Coppola, Deadline reports.

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This actor originally played Gregor Clegane, A.K.A. "The Mountain," in season one of 'Game of Thrones.'

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Holmes starred as Rachel Dawes, Batman’s lover, in 'Batman Begins.' However, she decided not to return for 'The Dark Knight.'

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Harris was the original Albus Dumbledore, appearing in the first two 'Harry Potter' movies.

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Whether it's because of scheduling conflicts or on-set drama, actors seem to get replaced all the time.

Curious about who has been replaced? Click through the following gallery and get to know some other high-profile cases.