The Other Marty

This is a phenomenon similar to The Other Darrin, but clearly distinct. It occurs when a part is recast after scenes have already been filmed with someone else in the role and, as a result, every scene the original actor did gets reshot. In some cases, quick shots of the original actor may find their way into the final cut, though you'd probably only notice this if you paused on those shots. It is, of course, much easier to pull off The Other Marty in animation.

Named for one of the more famous examples. Originally, Eric Stoltz was cast as Marty McFly in Back to The Future but after a good portion of the movie was filmed, the filmmakers, Bob Gale and Robert Zemeckis, decided that Stoltz's performance was too dark, and he was replaced by Michael J. Fox. Gale and Zemeckis actually wanted Fox from the start, but scheduling conflicts due to his work on Family Ties prevented him from accepting the role. In the final cut of the movie, Stoltz can be seen driving the DeLorean in wide shots of the car chase at the mall.

In a more general business sense, the use of stunt doubles and set doubles means that often we are not seeing the actual actor in as many scenes as we may believe. In animation, character models may be changed and updated as work progresses and completed footage may end with glimpses of that original character.

Related: What Could Have Been, The Pete Best.

Anime and Manga

 * Due to Creative Differences (read: really nasty falling-out) with ADV Films, the Director's Cut of the dub of Neon Genesis Evangelion replaces Tristan MacAvery with John Swasey as the voice of Gendo Ikari. While this does involve some change/added dialogue, it mostly consists of replacing pre-existing ones. This happened with several other voice actors too, but it's unknown if it's for the same reason (probably not).
 * In the dub of Eureka Seven Yuri Lowenthal had already recorded dialogue as Renton Thurston for the first thirteen episodes by the time it was decided his voice was too deep, and they re-recorded it with Johnny Yong Bosch, who played him for the rest of the series.
 * Bosch has mentioned at cons that this also happened with him in Trigun. He was apparently brought in to play Vash at the last minute after the original actor "didn't work out".
 * For the Toonami version of Tenchi Muyo! and Tenchi Universe in 2000, Rebecca Forstadt (who voiced Mihoshi since Tenchi in Tokyo and Pretty Sammy OAV 2) was hired to rerecord Ellen Gerstell's (Forstadt's predecessor for Mihoshi) lines in some episodes, for content reasons, and the fact that Gerstell wasn't available at the time.
 * Mobile Suit Gundam features a very strange example involving a mechanical design as opposed to an actor. The Compilation Movie trilogy replaces the goofy G-Fighter with the more sensible Core Booster as part of a general move away from the more Super Robot-ish aspects of the original series. The G-Fighter can still be seen in a couple of scenes that use footage from the TV show.
 * In what was one of the first warnings about ADV's troubles, Gurren Lagann was originally licensed by ADV Films, and several episodes (Word of God says 5) were dubbed before the show was suddenly yanked away and given to Bandai instead, who rerecorded the dub with another studio. Mentioning this at a con around one of the actors who was in the first dub tends to get... somewhat unpleasant results.
 * Two versions of Teknoman (an English dub of Tekkaman Blade) were released. The main character's lines were redubbed by Bob Bergen, but at the end of the episode that introduces General Galt one of his line readings is that of the original actor.
 * This scan from a 1997 issue of Coro Coro Comic seems to indicate that at one point, Yuji Ueda was planned to be the narrator of Pokémon as opposed to Unsho Ishizuka.

Film

 * Bride of the Monster. Loretta King replaced Ed Wood's girlfriend Dolores Fuller, because Wood believed King when she said she could finance the rest of the film. Fuller was given a minor role, and the one instance in the film in which the two actresses interact is... strained, at best. Give Fuller credit for keeping her cool and being a professional about the whole thing.
 * That's Dolores Fuller's version. Loretta King's is that Wood hired her flat out after seeing her in a play, and that Fuller was much less professional about the whole thing...
 * Happened on The Lord of the Rings when Stuart Townsend was playing Aragorn for two weeks before they replaced him with Viggo Mortensen. Word of God is that Peter Jackson decided Townsend was too young to play Aragorn, and he was replaced with Mortensen mere days before filming began.
 * Betty Hutton replaced Judy Garland in Annie Get Your Gun after MGM had recorded Garland's songs and filmed a few of her scenes.
 * Frank Morgan was cast as Buffalo Bill, but died just after filming one scene. He was then replaced by Louis Calhern.
 * Famously averted in Plan 9 from Outer Space - Ed Wood had filmed some scenes of Bela Lugosi before his death for another project, then after his death, cobbled together the unused footage into a role for that film, then filled in all the rest of the character's scenes with a different actor. (Who was, in fact, Ed Wood's wife's chiropractor.) They didn't even bother casting a stunt Lugosi that looked like him - they just had the new guy cover his face with a cape.
 * Also averted in Equilibrium, apparently because they couldn't afford to reshoot the scenes. As a result, two actresses are credited as playing the protagonist's wife: one as "Preston's Wife" and the other as "Viviana Preston".
 * Tyrone Power died after only filming a few scenes for Solomon and Sheba. He is still visible in some long shots.
 * James Purefoy was originally cast as V in V for Vendetta, and was replaced with Hugo Weaving. Since the character wears a mask throughout the entire film, the scenes that Purefoy had shot were not redone, and Weaving simply dubbed over the lines.
 * And since the mask muffled the voice so much, all the lines had to be redubbed anyway.
 * When Heath Ledger died during production of The Imaginarium of Doctor Parnassus, casting got creative and combined this trope with The Nth Doctor to have himself, Johnny Depp, Jude Law, and Colin Farrell all play his character.
 * And, in a Crowning Moment of Heartwarming, each of the replacements donated their salaries from the film to a fund for Ledger's daughter Matilda, since he had died before revising his will to include her.
 * Tom Cruise had told that he was interested but was denied since he was not actually a personal friend of Ledger like the other three.
 * Billy Wilder's Kiss Me, Stupid began filming with Peter Sellers in the key role of a struggling composer, but when Sellers suffered multiple heart attacks, the film was reshot with Ray Walston in the role.
 * In The Wizard of Oz, Buddy Ebsen (Jed Clampett from The Beverly Hillbillies) was originally cast as the Tin Man, but there was aluminum powder in his makeup and he grew very sick as a result of breathing it in. He was hospitalized two weeks into filming, and replaced by Jack Haley, whose makeup was made from aluminum paste. Haley completed the movie, and no footage of Ebsen as the Tin Man has been released, if it still exists; just photographs.
 * Ebsen can be heard, if not seen, in the finished film, when the four main characters sing We're Off To See the Wizard. (The Tin Man's solo numbers were presumably rerecorded by Haley.)
 * It gets even more convoluted by the fact that Ray Bolger had originally been cast as the Tin Man, but Bolger insisted on playing The Scarecrow, because it was the role played by his vaudeville idol Fred Stone. Ebsen reluctantly moved to the role of the Tin Man, not only lost the chance to be the one that Dorothy missed most of all, next to Chocolate Mousse, but ended up spending a couple of months in an oyxgen tent recovering from his lung infection.
 * In addition, the Wicked Witch of the West was originally supposed to have been played by Gale Sondergaard and the character was originally supposed to be a glamorous witch inspired by the wicked Queen in Snow White and the Seven Dwarfs. However, when producer Mervyn LeRoy decided that having an attractive Wicked Witch created a plot hole, as it played against the notion that only bad witches were ugly, the character was made into the familiar "ugly hag" and Sondergaard, looking hideous in the make-up, left the production and was replaced by Margaret Hamilton.
 * Comedians Ed Wynn and W.C. Fields were both considered for the part of the wizard, but wanted too much money, so the role went to another vaudevillian, Frank Morgan.
 * Frank Sinatra was originally cast as Billy Bigelow in the film version of Carousel. Because they had to shoot each scene twice - once in standard 35mm film and once in the new 55mm film - he left the production, and Shirley Jones' Oklahoma! co-star Gordon MacRae was cast instead. Though nothing was ever filmed, they had started sound recordings before Sinatra left. Ironically, a few weeks into production, a conversion process was discovered, rendering multiple takes unnecessary.
 * Not sure whether this is an example, or sort of a reversal of this trope: in The Incredibly Strange Creatures Who Stopped Living And Became Mixed-Up Zombies the actress who was to play the "good girl" love interest got fired before filming any of her scenes, which should have saved the film from this. However, she was replaced by Sharon Walsh, an extra who HAD already shot some scenes, and can still be spotted as an anonymous dancer in a couple of musical numbers. One actress/two parts rather than two actresses/one part; does that count?
 * Thomas And The Magic Railroad originally had John Bellis voicing Thomas and Michael Angelis (the UK narrator of the show) voicing Percy and James. Bellis was replaced with Eddie Glen and Angelis was replaced with Linda Ballantyne (as Percy) and Susan Roman (as James), as test audiences found that they sounded too old and their Liverpudlian accents too thick. On a lesser scale, Neil Crone, the voice of Diesel 10, originally delivered his lines in a Russian accent, only to have to re-record them without it.
 * Interestingly, since Eric Stoltz was The Other Marty in Back to The Future, J. J. Cohen was actually the other Biff. Originally, Cohen was cast as Biff Tannen, but he didn't look so imposing next to Stoltz, so Thomas F. Wilson was cast as Biff while Cohen was recast as Skinhead, one of Biff's mooks. (It probably helped in recasting Marty that, height differences aside, Eric Stoltz and Michael J. Fox look very similar.)
 * The TV show Fringe had some fun with this: in a scene set in the alternate universe in 1985, "Back To The Future starring Eric Stoltz" is displayed very prominently on the front of a movie theater.
 * Despite the fact that they shot with Stoltz for five weeks, the studio has been extremely reluctant to release that material - until the Blu-Ray release, the only publicly released footage of Stoltz as Marty was still images. The Blu-Ray release has, for the very first time, actual video of Stoltz as Marty - as part of a half-hour bonus feature covering pre-production as a whole, with his scenes amounting to about ten seconds total, with no audible dialogue.
 * Footage of Stoltz as Marty survives in the finished film during the scene when Marty is trying to outrun the terrorists. Much of the driving footage features Stoltz behind the wheel though he is barely visible through the windshield.
 * In You Only Live Twice, Czech actor Jan Werich was originally cast as Blofeld, but he fell ill during filming, thus being replaced by Donald Pleasence.
 * And that Jan Werich reminded the production crew of Santa rather than a supervillain. Donald Pleasence, on the other hand...
 * The role of Willard in Apocalypse Now was originally played by Harvey Keitel, but he was fired about a week into shooting and replaced by Martin Sheen. Sheen later suffered a heart attack during filming, and several scenes in the finished film actually feature his stunt double brother Joe Estevez instead.
 * Nedra Volz replaced Edith Massey when she passed away, in Lust In The Dust.
 * In the film version of The Fugitive, Richard Jordan was originally cast as Dr. Charles Nichols, but he was extremely ill (he ended up passing away a few weeks after its release), thus being replaced with Jeroen Krabbe.
 * Dulcea's first actress in Mighty Morphin Power Rangers The Movie, Mariska Hargitay, left during filming and all her scenes had to be reshot with Gabrielle Fitzpatrick.
 * It's a bit more complicated than that. Gabrielle Fitzpatrick was originally slated to play Dulcea, but had surgery that conflicted, so Mariska Hargitay stepped in. When filming ran long, Fitzpatrick was able to return to the role, but some scenes involving Dulcea training the Rangers couldn't be reshot and were cut entirely.
 * James Remar was originally cast as Cpl. Hicks in Aliens, but James Cameron had him replaced with Michael Biehn a few days into shooting. A few shots of Remar from behind still made into the film.
 * Practically the entire cast of The Room (save for Tommy Wiseau himself) was swapped during the shoot: For instance, the actor who portrays the love interest, Lisa, was originally a stagehand. One of the more obvious instances is Pete, the psychiatrist character, whose actor quit before his scenes could be finished. Rather than get a new actor, Tommy Wiseau kept all the scenes that had been shot, and simply put another, never before seen character in the film's finale, where he catches Lisa and Mark together and berates them for betraying Johnny.
 * In 1954 Abbott and Costello were shooting a comedy called Fireman Save My Child when Lou Costello fell ill and had to drop out of the film. Universal replaced Abbott and Costello with Hugh O'Brian and Buddy Hackett, and made Spike Jones and his City Slickers - originally just guest stars - into the main attraction. Abbott and Costello are still visible in the completed film, in some long shots.
 * During the filming of The Matrix Reloaded, Aaliyah died in a plane crash and was replaced by Nona Gaye, and all previously filmed scenes were subsequently reshot.
 * Who Framed Roger Rabbit? has a visual example: Originally Jessica Rabbit had a different design. It can still be seen in the patty cake photos when Eddie spots the will.
 * In Flight of the Intruder, for the court martial scene, the prosecutor was played by Ed O'Neill. During a test screening, the moment O'Neill appeared onscreen in his army uniform, there was laughter from the audience because of O'Neill's other role, Al Bundy on the sitcom Married... with Children. The scene had to be reshot with Fred Thompson playing the role.
 * Dennis Hopper had been cast as Christof in The Truman Show, but left over creative differences with director Peter Weir. His replacement, Ed Harris, was nominated for a Best Supporting Actor Oscar for playing Christof.
 * Kel O'Neill was originally cast as Eli Sunday in There Will Be Blood only to be replaced two weeks into the shoot with Paul Dano (who interestingly enough already played a bit part as Eli's brother Paul, thus turning them into twin brothers). An article on The New York Times Magazine claimed this was because O'Neill was intimidated by Daniel Day-Lewis' notorious intensity and tendency to remain in character off set though both Day-Lewis and the director denied this.
 * Joe Dirt's parents were originally played by Roseanne Barr and Gary Busey, but the director felt Roseanne's star power, in particular, was too distracting. So their scenes were reshot with Caroline Aaron and Fred Ward.
 * Klaus Maria Brandauer was originally cast as Captain Marko Ramius in The Hunt for Red October, but two weeks into filming, quit because of other commitments. He recommended Sean Connery, with whom he starred in Never Say Never Again, to take over the role.
 * Shrek was originally supposed to be a vehicle for Chris Farley but Farley died before he could complete recording and was replaced by Mike Myers.
 * And, in an audio version of this trope, Myers originally recorded the whole role in an American accent before deciding that Shrek should sound Scottish.
 * Actor John Finch had been cast for Alien but had fallen very ill due to his diabetes and was replaced by John Hurt.

Live Action TV

 * Subverted in ''The Big Bang Theory. In the pilot Penny did not appear in her place was a character named Katie played by Amanda Walsh who was more of a streetwise tough girl compared to Penny. The show wasn't picked up and sat in Development Hell until the show was revamped and Kaley Couco was cast as Penny.
 * In the remake of Bionic Woman Mae Whitman was originally cast as Becca Sommers in the pilot.The character was retooled for the series and Lucy Hale was cast instead
 * Cheers. Ex-football player Sam Malone was initially Fred Dryer. When he was replaced by Ted Danson, Sam became an ex-baseball player due to Danson's thin frame. Dryer would have a recurring role as Sam's sports reporter friend Dave Richards. Julia Duffy was originally cast as Diane Chambers. She appeared in one episode in Season 1 as Diane's best friend Rebecca Prout.
 * Happened with Jenna in Thirty Rock. In an unaired version of the pilot, she was played by Rachel Dratch. Months after the original filming was completed, Dratch was replaced by Jane Krakowski. The part of Cerie was also recast between the two pilots.
 * Miniseries V originally had Dominique Dunn as Robin Maxwell. She was murdered halfway through production and was replaced by Blair Tefkin. Dunn can be seen, from behind, in a wide shot watching the Mother Ship arrive above an LA suburb.
 * The pilot for Firefly had Rebecca Gayhart as Inara. Joss Whedon knew it wasn't going to work out with Gayhart, so he had all of Inara's scenes filmed separately, so when he finally cast Morena Baccarin, it would be easy to replace them all.
 * This revelation had the side effect of making the rest of the cast right freaked out by Joss Whedon's Chess Mastery.
 * At least some of Sharpe's Rifles was shot with Paul McGann as Sharpe, but owing to an injury he had to be replaced by Sean Bean.
 * The role of Mark on Step by Step was originally played by dark-haired boy who looked nothing like the regular actor. You can catch glimpses of him in the title sequence of early episodes, though the role was apparently recast before the show aired.
 * Richard Kiel (Jaws from James Bond) was originally cast as the Hulk in the live-action TV version of The Incredible Hulk; he can still be seen in some shots in the opening credits.
 * Colm Meaney as Gene Hunt and the rest of the Los Angeles cast from the initial pilot episode of the American Life On Mars. Replaced by Harvey Keitel and a setting switch to New York City.
 * The Star Trek: The Next Generation episode "The Most Toys" was originally cast and some scenes shot with David Rappaport as Kivas Fajo. He committed suicide during production, and the part was recast and reshot with Saul Rubinek.
 * In a costuming version, Jadzia Dax from Star Trek: Deep Space Nine was a Trill, a species introduced in TNG with distinctive head ridges. In trying out the prosthetics for actress Terry Farrel, even though it was Michael Westmores' typical quality with a softer female look, they felt it took away from how attractive she was and would be more trouble than it was worth for a long running series. So they went with a spotted skin design they used for a completely different character and species on TNG, which ended up effectively retooling the Trill design and no mention of the change was made.
 * Genevieve Bujold was originally cast as Nicole Janeway on Star Trek: Voyager. When she bailed from the show after only three days of filming, she was replaced by Kate Mulgrew as Kathryn Janeway. This is quite possibly the most brilliant thing the producers ever did with Voyager, because while fans take issue with just about every aspect of the show, almost all of them - including such prominent critics as SF Debris and Confused Matthew - agree that Mulgrew's performance is by far the best thing going for the character.
 * The opening episode of Doctor Who's fourth series, "Partners in Crime", was to feature Howard Attfield as Donna Noble's father Geoff (Attfield had previously played the role in "The Runaway Bride"). Attfield died after filming, and rather than recast the actor, Bernard Cribbins' character Wilfred Mott was retconned to be Donna's grandfather, and Attfield's scenes were reshot with Cribbins.
 * "The Time Warrior" initially featured April Walker in the role of Sarah Jane Smith. However, when Jon Pertwee showed his disatisfaction of her casting (according to him, her stature was too strong to fit the role of a Doctor Who companion), then-producer Barry Letts recasted Elisabeth Sladen in the role with Pertwee's approval.
 * Happened to the opening credits of Threes Company after Jenilee Harrison left the show (although she wasn't replaced, just dropped entirely). All group footage (filmed at the LA Zoo) with her in it was reshot. She can sometimes be seen very briefly at the beginning of the credits in the episodes after her departure.
 * Smallville had the entire pilot filmed with Cynthia Ettinger playing Martha before they reshot it with Annette O'Toole. The original version is out there listed as either "Unaired pilot" or "Episode 0".
 * The first Seinfeld episode to feature George's father Frank Costanza originally aired with this character being played by John Randolph. Later, when Jerry Stiller was cast in this role, producer Larry David had those first scenes of the character re-shot with the new actor, specifically for the series' syndication.
 * Jerry's father Morty Seinfeld was played by Barney Martin who replaced another actor.
 * Mighty Morphin Power Rangers featured a different actress (Audri DuBois) playing Trini in the original pilot version of "Day Of The Dumpster". She was replaced with Thuy Trang for the proper version. The only shot of her that remains in the proper version is when the rangers exit the Command Center. A different voice actor was also used to voice Finster, who was also replaced in the proper version.
 * Likewise, Emma Simms was originally cast as Maya in Power Rangers Lost Galaxy, but left after the first two episodes.
 * In Cybertron, the unaired pilot of VR Troopers, Jason David Frank (best known for his role as Tommy Oliver in various incarnations of Power Rangers) played Adam Steele. When JDF was forced to leave the project in order to return to Power Rangers, Brad Hawkins replaced him and the character was renamed Ryan Steele in the series itself.
 * VR Troopers originally had a different actor playing Professor Hart. This early version of him was a Caucasian old man and had a different personality to the one who appeared in the series proper. Footage of him can be seen in the early VR Troopers promo included with the Mighty Morphin Power Rangers Fan Club video.
 * For the Buffy the Vampire Slayer original pilot, Riff Regan played Willow, but apparently she was never intended as playing the series character, just a stand in for the "proof of concept" pilot.
 * That pilot also had Stephen Tobolowski as the principal.
 * The role of Emma Peel on The Avengers was originally given to Elizabeth Shepherd. After one episode was completely filmed and a second in the process of being filmed, she was let go and replaced with Diana Rigg. The first Emma Peel episode was completely reshot to accommodate the change.
 * When Carla Bonner replaced Emma Roche as Stephanie Scully in Neighbours after a few weeks of filming, almost all her scenes were reshot. However, Roche can be seen briefly through the car window when Steph drives her sisters into Ramsey Street.
 * Growing Pains had a different actress, Elizabeth Ward, playing Carol in the pilot; her scenes were reshot with Tracey Gold. This has been mysteriously forgotten about; Ward's name is rarely, if ever, mentioned, and little to nothing is known about her.
 * Bob Saget replaced John Posey in Full House; this is why Michelle seems somewhat older when Danny walks in the room. Reportedly, series creator and executive producer Jeff Franklin wanted Saget from the start, but he was unavailable due to being employed as a "comic correspondent" for CBS' short-lived "Morning Program" newscast.
 * It happened for a lot of characters on Game of Thrones between the original pilot and the series proper (most of the pilot was then reshot with the new cast).
 * Daenerys Targaryen went from Tamzin Merchant to Emilia Clarke
 * Catelyn Stark went from Jennifer Ehle to Michelle Fairley
 * Magister Illyrio Mopatis went from Ian McNeice to Roger Allam
 * Gared went from Richard Ridings to Dermot Keaney
 * Ser Waymar Royce went from Jamie Campbell Bower to Rob Ostlere
 * Leonard Driscoll, the head of the secret agency Intersect from Gemini Man was played by Richard Dysart in the pilot, and recast with William Sylvester by the time the series began filming. Both actors can be seen playing the same part in Riding With Death, a TV movie combining a few episodes of the series, which was famously made into an episode of Mystery Science Theater 3000.
 * In the unaired pilot for Charmed that was made to sell the show to the WB, the role of Phoebe was played by an actress named Lori Rom. When the show got picked up and went to series, she (and several other actors) were replaced, and the pilot was reshot. While no footage of Rom seemed to survive to the aired pilot, it is noticeable that some footage from the unaired pilot survived. The two pilots were shot at different times of the year, as the trees and greenery showed.
 * The pilot for Masked Rider featured different actors for Molly and Albee as well as different voices for Magno and Chopper (the former having a male voice, rather than female as seen in the final product).
 * Nearly everyone from the Being Human (UK) original pilot was recast in the actual series, with the exception of George.
 * Jill Taylor in Home Improvement was first played by Frances Fisher but was then replaced after audiences reacted poorly to her performance. Patricia Richardson played her for the rest of the series.
 * Richard Karn who plays Al Borland was nearly this. He was a fill in for Stephen Tobolowsky, who was supposed to play a character named Glenn, at the time was busy with a film role. Unable to break a second film commitment, Karn was permanently cast as the role for Al on Tim Allen's Recommendation and Glenn enden up not appearing.

Music

 * There was at one time a rumor that Little Steven Van Zandt had fallen victim to this trope when he left Bruce Springsteen and the E Street Band in 1984 (rejoining in 1999). Allegedly, a number of songs on the ''Born in the USA" album were re-recorded with Bruce on lead guitar instead of Van Zandt. In actuality, Van Zandt left before he would have had the chance to appear on those sessions. In any case, Springsteen always played a lot of the lead guitar on his albums even while having another dedicated guitarist in the band.
 * When Michelle Phillips briefly left The Mamas And The Papas during the recording of their self-titled second album, her parts were recorded by producer Lou Adler's girlfriend, Jill Gibson. Michell returned before the album was released, and re-recorded at least some of her parts. It remains a matter of dispute as to how many songs on the final album feature which singer.
 * The vocals on Black Sabbath album The Eternal Idol were initially recorded by Ray Gillen, but he quit due to personal financial difficulties (among other problems) just before the release and Tony Martin was then hired to rerecord in a nick of time.
 * Ozzy Osbourne was at one point sued by his former bandmembers Bob Daisley and Lee Kerslake for unpaid royalties. When the albums featuring them (Blizzard of Ozz and Diary of a Madman) were reissued in 2002, their parts were rerecorded by Ozzy's then-current members.
 * Glen Matlock is simultaneously on both sides of this trope. He was replaced by Sid Vicious when the rest of the band decided they couldn't stand him halfway through the recording of their only (studio) album Never Mind the Bollocks, Here's the Sex Pistols. Then, they found out that Sid was often strung out on various drugs, and when he was sober he was completely incompetent as a bassist. So they called Matlock back to finish the session, though the album is officially credited to Vicious.

Theatre

 * With The Phantom of the Opera Steve Harley, a UK singer trying to make a comeback, was in running for the role of the Phantom -- so much so that he recorded the original single of the "Phantom of the Opera" title song. However, the tone and the musical style of the show changed considerably after this, and he was sacked just before rehearsals began and replaced with Michael Crawford. Needless to say, the comeback never happened.
 * Spider Man Turn Off the Dark cycled through many principal actors because of its constant delays and unfortunate production mishaps. At one point, Jim Sturgess was attached to play Spider-Man, with Evan Rachel-Wood as Mary-Jane and Alan Cumming as the Green Goblin.
 * In the world premiere of the musical First Date at Seattle's ACT Theatre, Casey was originally supposed to be played by Kendra Kassebaum (one of the many Glindas in Wicked), but she got called back to NYC for a different show and was replaced by Kelly Karbacz.

Western Animation

 * Disney had finished recording Aladdin and the King of Thieves with Dan Castellaneta as Genie (Robin Williams had voiced Genie in the original movie only, and Castellaneta had replaced him for the TV series and The Return of Jafar). Then, when the filmmakers managed to persuade Robin Williams to return for King of Thieves, they just threw out Castellaneta's work and re-recorded all of Genie's lines.
 * The illustration of Aladdin himself is another Marty -- his initial design was even based off of Michael J Fox. He, after almost half of the film was drawn, was redesigned to look more like Tom Cruise for better appeal -- the DVD Commentary sets points out when this starts to become more obvious.
 * Chris Farley was attached to Shrek early in its development, but after his death (and many story changes) the role went to Mike Myers -- who then performed an odd same-actor version of this trope, switching to a Scottish accent partway through and re-recording already-done lines.
 * Cal in Cloudy with a Chance of Meatballs was originally voiced by Tracy Morgan, but was replaced by Bobb'e J. Thompson at some point late in the production, as the art book still lists Tracy Morgan as Cal's voice actor, and a number of animation reels still have his voice in them. (This can be seen at 0:50 and 1:37 here.)
 * In the reruns of the Fairly Oddparents shorts from Oh Yeah! Cartoons, Tara Strong redubbed Timmy's lines, presumably out of respect for Timmy's original voice actress, Mary Kay Bergman, who committed suicide in 1999.
 * For The Jetsons: The Movie, Janet Waldo was originally going to reprise her role as Judy Jetson, and apparently recorded her lines for the film, but she was replaced by Tiffany (who was originally only supposed to be Judy's singing voice), at the insistence of Tiffany's manager.
 * Also both of the lead male voice actors Mel Blanc (Mr. Spacely) and George O'Hanlon (George Jetson) died during filming. Jeff Bergman dubbed some of their remaining lines. (Listen carefully in the scene where Spacely gives George the promotion. Both of their voices subtly change halfway through.)
 * Karri Turner was originally supposed to be the lead voice actress for South Park and appeared in the unaired pilot as Wendy, Ms Crabtree, and the other female characters. She wound up replaced by Mary Kay Bergman in the series proper, as the creators felt her voice wasn't distinct enough. Interestingly, the first choice before Turner was Nancy Cartwright, who refused to work on the show due to its crude content.
 * Probably for the best, given what happened with fellow Scientologist Isaac Hayes (the voice of Chef) after the Scientology parody episode.
 * All of the classic Gumby episodes were redubbed in 1988 so they would match up with the then-new Gumby Adventures TV series. In addition to replacing John Seely's stock music with a synthesizer score, all the voices were rerecorded by the then-current voice cast. Gumby had quite a few voice actors and actresses in the original episodes, including Dick Beals, Ruth Eggleston, Dallas McKennon (in the early 1960s) and Norma MacMillan (in the late 1960s). In the redubbed versions, Dallas McKennon voiced Gumby in all the episodes.
 * The pilot of Inspector Gadget (where Gadget has a mustache) had Mona Marshall as the voice of Penny, but for the rest of the first season, she was played by Cree Summer.
 * In the first produced episode of The Simpsons, "Some Enchanted Evening", Christopher Collins (aka Chris Latta of Transformers and G.I. Joe fame), besides voicing a TV host, recorded Moe's lines before they were dubbed over by Hank Azaria, who assumed the part from then on. Christopher Collins also was the other Mr. Burns in the episode "Homer's Odyssey", which was Burns' first appearance in production order (but not broadcast order).
 * Originally in Were Back a Dinosaurs Story, John Malkovich was the original voice of Professor Screweyes, about midway through production he was replaced by Kenneth Mars, some snippets of his voicework along with the deleted scenes with explanation for his missing eye and the crows can be seen here.
 * In the King of the Hill episode "My Own Private Rodeo", Charles Nelson Reilly was the original voice of Dale Gribble's estranged gay father Bug. After the story was rewritten, David Herman did Bug's voice instead.
 * Before Mark Hamill took over, Tim Curry was in fact the voice of The Joker in Batman: The Animated Series, but Curry didn't make it through three episodes without hurting his throat and Mark Hamill became well received for his work in "Heart of Ice".
 * Normally, Jeremy Irons not only provided the speaking voice for Scar, the main villain of The Lion King, but also his singing voice as well, but toward the end of the song "Be Prepared", Irons almost stressed his vocal cords, and as a result Jim Cummings (who voiced Ed the hyena) had to finish Scar's singing because of this.
 * In Bolt, Chloe Grace Moretz is the first choice to voice the role of Penny, and apparently voiced the character for the entire film. But she is quickly replaced by Miley Cyrus, who went on to re-record most of Penny's dialogue, even though Moretz's voice for Penny as a child still remains.
 * Jim Varney of both Ernest P. Worrell and Toy Story fame was supposed to play the role of Cookie Farnsworth in Atlantis the Lost Empire, but just right before production of that film was finally over so it can be released, Varney died of cancer and as a result Steve Barr had to finish the rest of Varney's dialogue for Cookie. Atlantis was actually Jim Varney's final role in film history.
 * Varney took that role knowing he would never see the finished product. Now that's dedication to your craft.
 * In later airings of Arthur during the Justin Bradley episodes over half of them were redubbed by his then current voice actor Mark Rendall.
 * Sterling Holloway was supposed to be the voice of Opus in A Wish for Wings That Work, but much to Berkeley's annoyance, it got changed to Michael Bell.
 * A very controversial one happened in Avengers: Earth's Mightiest Heroes. It was recently revealed that Josh Keaton had originally reprised his role as Spider-Man for the episode "Along Came a Spider", but then it was decided to have Drake Bell redub the lines.
 * When Recess premiered, Ryan O'Donohue played Gus in the episode's initial airing. Once Courtland Mead took over the role in episodes after that, he redubbed his lines for the reruns (Ryan O'Donohue continued to play Randall and Dave, among others).