Same Language Dub

Sometimes a character is voiced, in the same language, by someone other than the actor who physically portrays them. Dubbing an actor's lines in general is a standard industry practice, especially when filming special effects shots or in places with too much background noise - this trope happens when that voice is provided by a different actor.

For cases where singing is what's being dubbed, see Non-Singing Voice.

Film

 * Hercules In New York: The original release had Arnold Schwarzenegger's voice dubbed over by someone much more intelligible. The DVD release features Arnold's undubbed voice. It's pretty painful.
 * Interestingly, Hulu has the dubbed version on their site, while YouTube hosts the original version. Oddly enough, the Hulu version is missing the music soundtrack.
 * Forrest Gump includes scenes where Tom Hanks' performance was mixed with historic footage. To record the voices of the historical figures, voice doubles were hired and special effects were used to alter the mouth movements for the new dialog.
 * While Peter Dobson played Elvis in the "hotel" scene, Kurt Russell dubbed his lines, while the real deal sang on TV via archival footage.
 * In-story example: In Singin in The Rain, Lina Lamont's nails-on-a-blackboard voice is dubbed over by Kathy. The original plan is for this to be a springboard for Kathy's career, but Lina has other plans.
 * Interestingly enough, the trope was also used in production in some interesting ways. Lina's actress dubbed over herself with her real speaking voice when Kathy is supposed to be speaking for her. Additionally, Kathy's actress only actually sang "Good Morning" and "Singin' in the Rain", but not on "Would You?" or "You Are My Lucky Star", where Betty Noyes dubbed over the person who was supposedly dubbing over another person in-story.
 * Examples from the Star Wars series:
 * In the original trilogy, the actor in the Darth Vader suit on-screen was David Prowse; the voice was provided by James Earl Jones, who was uncredited until later re-releases. In Revenge of the Sith, it's Hayden Christensen in the suit, and an uncredited actor providing the voice. It's believed to be Jones again, but he has never confirmed it. On the DVD commentary, it's mentioned that the voice actor will always remain uncredited, but any true Star Wars fan "should know the answer".
 * Both actors playing Wedge Antilles in A New Hope - Denis Lawson and, in the briefing scene, Colin Higgins - were dubbed by David Ankrum. Lawson went on to play Wedge in the next two movies and finally got to use his own voice in Return of the Jedi.
 * In A New Hope, the actress playing Beru Lars was dubbed over because George Lucas thought her voice was too low.
 * In The Phantom Menace, Darth Maul was played Ray Park with his lines (all three of them) dubbed over by Peter Serafinowicz.
 * In Midway, you see Toshiro Mifune, but hear Paul Frees.
 * Neil Connery (Sean Connery's brother) stars in Operation Double 007, but his voice is dubbed by an American actor.
 * It's a fairly common practice to have the original actors redub (or "loop") their own scenes, most often for scenes shot on locations with a lot of background noise. The James Bond movie series was unusual in that for many years, they would loop all dialogue in post-production. The producers frequently would use the occasion to replace an actor, most often, but not invariably, to replace the voice of a heavy-accented foreign star. Every pre-Roger Moore Bond film has at least one example of this trope for a prominent character:
 * Ursula Andress was dubbed by two separate actresses in Dr. No: Nikki Van der Zyl looped Andress' voice to preserve a mild version of her natural accent, while her singing voice was dubbed by Diana Coupland. In the same film, Van der Zyl's voice was used to dub the other Bond Girl - Eunice Gayson as Bond's London girlfriend Sylvia Trent.
 * In From Russia with Love, Daniella Bianchi's dialogue (as Tatiana Romanova) was overdubbed by Barbara Jefford to hide her thick Italian accent.
 * In Goldfinger, all of Gert Fröbe's (Auric Goldfinger) dialogue was dubbed by British actor Michael Collins, due to Fröbe's poor command of English. The looping was planned from the start, with Fröbe instructed to speak his lines quickly to make the process easier. Curiously, Fröbe's own voice can be heard in the movie's trailer, perhaps because the looped dialogue had not yet been recorded.
 * The main villain's voice was dubbed again in Thunderball, where Robert Rietti's voice replaced Adolfo Celi's. The aforementioned Nikki Van der Zyl turned up as well, this time overdubbing Claudine Auger's French accent in the role of Domino.
 * Robert Rietti's voice was heard again in You Only Live Twice in the role of Tiger Tanaka, though Tetsurô Tanba's own voice is still heard for his Japanese dialogue.
 * In On Her Majesty's Secret Service, Bond spends a considerable portion of the movie impersonating genealogist Sir Hillary Bray. Curiously, Bond's "in character" lines as Bray were actually dubbed by George Baker, who played the real Bray in an earlier scene. It remains unclear whether this was done to demonstrate that Bond is a truly masterful vocal mimic, or because of a perceived deficiency in George Lazenby's performance. In the same movie, Joanna Lumley played "the English girl" among the bevy of international beauties who are Blofeld's patients. Lumley also ended up dubbing the lines for several of the other girls in accented English.
 * Lana Wood's Plenty O'Toole was dubbed in Diamonds Are Forever.
 * The series gradually moved away from this trope during the Roger Moore era, but Barbara Jefford stepped in to provide the voice for Caroline Munro's character, Naomi, in The Spy Who Loved Me.
 * Because the only camera the producers had couldn't sync up with a microphone, all dialogue in Manos the Hands of Fate was dubbed after the fact. Only Michael, Margaret, and the Master were dubbed by their actors; everyone else, including Torgo, was same-language dubbed.
 * When Mad Max was released in the US, the entire cast, except for Mel Gibson, was re-dubbed by American actors to eliminate the cast's thick Aussie accents.
 * Watching Master Tatsu in the first two Teenage Mutant Ninja Turtles movies, you're seeing Toshishiro Obata, but hearing Michael McConnohie.
 * Similarly, Shredder is played by James Saito but voiced by David Mc Charen.
 * When you're watching the 1984 movie Greystoke you're looking at Andie MacDowell, but hearing Glenn Close.
 * The first 20 minutes of Trainspotting were redubbed to make the thick Scottish accents comprehensible to an American audience. The Region 1 DVD releases restored this, however.
 * On Flash Gordon, Sam J. Jones' voice was overdubbed by an uncredited actor whose identity remains a mystery to this day after Jones refused to return for post-production.
 * On Cyborg, Vincent Klyn's voice was overdubbed by an uncredited actor.
 * The Danish Kaiju film Reptilicus was shot with the cast phonetically speaking their lines in English to make it easier to sell in America, but the cast's thick accents forced its American distributors to re-dub the entire film.
 * In the Tim Burton film Ed Wood, Orson Welles was played by Vincent Donofrio, but dubbed over by Maurice LaMarche.
 * The children's film Napoleon was originally made in Australia with Australian voice actors, but when it was brought Stateside, all of the voices were replaced with American ones, despite the movie explicitly taking place in Australia. They could get away with it (from a technical point of view) because it's a talking-animal movie where the animals "talk" with their mouths closed, Homeward Bound style.
 * In The Avengers 1998, a character at one point drops an F Bomb...but it's quite clearly been dubbed in, as it sounds nothing like the character's previously heard voice and the actor's lips do not move. This was done to bump the film up from a PG to a PG-13, in hopes to draw fans to the film (which had been postponed from its original release date due to terrible test screenings, and was subsequently Not Screened for Critics).
 * Played with in Attack of the Killer Tomatoes. The Japanese scientist speaks in poorly dubbed English, like a character in a Godzilla movie.
 * The Scottish film Gregory's Girl was dubbed for US release with weaker accents. Both versions are on the US DVD.

Live-Action TV

 * In the Mighty Morphin Power Rangers episode "Big Sisters", Maria (the young girl Trini and Kimberly are looking after), is obviously and poorly dubbed over by a completely different actress.
 * In the Twilight Zone episode "The Bewitchin' Pool", veteran voice actress June Foray dubbed a few of Mary Badham's lines, in which her accent was deemed unintelligible.
 * Announcer Charlie O'Donnell, longtime announcer of Wheel of Fortune, died in November 2010. Since the show tapes in a very Out of Order fashion, this means that he ended up announcing episodes that would air after his death. As a result, Wheel dubbed him over with different announcers.

Video Games

 * Seven of Humongous Entertainment's games had entirely redone dubs specifically for the UK. They probably wouldn't have gotten much recognition had the UK dub of the first Spy Fox game not been mistakenly exported to the US.
 * The UK and Australia versions of the Professor Layton games are based on the US English translation, but change the voice actor for Luke because the American's Fake Brit is very obvious to actual Brits (the Professor's voice is also a case of Fake Brit, but done well enough to not be an issue and remains).
 * James Bond 007: Nightfire (the one released for consoles) features levels set in Japan with Yakuza thugs and female that speak Japanese. These are replaced with different Japanese voices in the Japanese release.

Western Animation

 * When Robbie the Reindeer: Hooves of Fire was aired on CBS for the first time in 2002, its British voice cast was dubbed over with an all-star cast. Only Hugh Grant remained.
 * In-Universe example in Total Drama World Tour: The cast watch a Japanese trailer for Action, and their voices are dubbed over, still in English. Chris says it's because the locals didn't like their real voices.
 * A weird case of this happens in the Argentinian animated movie Boogie El Aceitoso when it was bringed to Mexico: Only the titular character, Boogie, and his love interest, Marcia, are dubbed by Mexican actors, but the rest of the characters retained their original voices. While this is pretty normal with some Argentinian media in Mexico due of the Argentinian accents, in this case it was due of a mix of both cultural and legal reasons: Since those two characters are the ones who spew most of the racist and xenophobic slants used in the movies, and recently Mexican laws forbids the use of discriminatory language, their voices where redubbed to remove or toning-down those dialogues. Luckily, since the movie was voiced using a neutral accent rather than using the Argentinian one, this is was barely noticed.
 * The World of David the Gnome was redubbed in Mexico with Mexican voice actors due to the performers' Spanish accents in the original version.