History SuspiciouslySimilarSubstitute / LiveActionTv

** Justin from ''Series/PowerRangersTurbo'' serves as one to two characters. He is one to [[Series/MightyMorphinPowerRangers Billy's]] taking over the role as the nerdy Blue Ranger though this is a downplayed example due to the difference in age. He also fills the role of [[Film/MightyMorphinPowerRangers Fred]], serving as a KidAppealCharacter introduced in a movie, though unlike Fred, Justin actually does become a Ranger and sticks around for the series.

* Uncle Albert for Grandad on ''Series/OnlyFoolsAndHorses''. More blatant in his first few appearances, in which he was just filling the role that Grandad would have filled if not for Lennard Pearce dying, but he soon started to be portrayed as being more physically capable and less of a Cloud Cuckoolander than Grandad, along with his navy background playing a more important part in episodes.

* ''Series/TheSopranos'' killed off the character of Richie Aprile in the twelfth episode of the second season. In the second episode of the third season, Ralphie is introduced. Although you could never mistake them for each other, they occupy very similar places in the show's universe; he even ends up dating Janice.

* Put-upon straight man, oftentimes OnlySaneEmployee, and Leslie's original love interest Mark Brendanawicz leaves ''Series/ParksAndRecreation'' at the end of Season 2, the same time put-upon straight man, OnlySaneEmployee, and Leslie's love interest Ben Wyatt joins the cast.

* Done on ''Series/AlloAllo'' when Mimi and Captain Bertorelli appeared as substitutes for Maria and the German Captain Hans respectively -- in particular, Mimi was at least as short as Maria and both had fiery tempers. It allowed them to continue the gag of Mimi/Maria having to get a stool to stand on in order to hug René. Later, Monsieur Leclerc was replaced by his twin brother after the original actor died. Captain Bertorelli and the second Leclerc were ''then'' replaced in a TheOtherDarrin manner. In the final season, the actor playing "Herr Flick of the Gestapo" was replaced - this was explained as him having plastic surgery to prepare for Germany losing the war. Also parodied in the series, when René's death was faked and he was forced to pose as his own Suspiciously Similar Substitute twin brother for the rest of the show.
-->'''René:''' I am ''also'' named René.

* To an extent, Creator/HughLaurie in the third and fourth series of ''Series/{{Blackadder}}'' seems to have filled this role (aristocratic fop) in replacement of Tim [=McInnerny=] from the first two series, after [=McInnerny=] left because he didn't want to be typecast. When [=McInnerny=] rejoined the regular cast in the fourth series, his character resembled that played by Stephen Fry (brown-nosing rival) in the second series, with Fry in turn now playing a character more akin to that of Creator/{{BRIAN BLESSED}} and Miranda Richardson respectively (insane tyrant) in the first two series. This slightly convoluted game of "musical chairs" in regards to actors and characters appears however to have been of little detriment to the series.

** Then, when Creator/JonathanBanks left the show due to commitments to ''Series/BetterCallSaul'', Buzz was replaced with Elroy Patashnik, ''another'' GrumpyOldMan, this time played by Creator/KeithDavid. Despite some major differences (Elroy was a genius, black and not a prior Greendale student), it was clear the writers were using him to fill the same basic role. As Elroy joined the cast after both Creator/DonaldGlover and Yvette Nicole Brown had left the series as well, he also had to step in for Troy and Shirley as the group's new [[TokenMinority token black member]]. All this was actually {{lampshade|Hanging}}d at one point:

** The series did this in its final season with Pete (Creator/JakeLacy) and Clark (Clark Duke) being immediately {{lampshade|Hanging}}d as the "new Jim and Dwight", due to their resemblance to younger versions of both characters. They did this despite both Jim ''and'' Dwight still being around.

* On ''Series/TwoAndAHalfMen'', Clark Duke looks so much like a younger Angus T. Jones that a casual observer might think they are brothers. In fact, in one episode everyone, even Alan, confuses Walden's new intern Barry for Jake.

** BBC ExecutiveMeddling really, ''really'' wanted Creator/MattSmith's Eleventh Doctor to be as much like Creator/DavidTennant's Tenth Doctor as possible, fearing a more unusual character would not be as relevant and popular; there had even been discussion of outright re-cancelling the show, this time for good. The original proposed outfit for the character even followed a similar "'90s indie kid" aesthetic by way of a pirate outfit, but Smith strongly disliked it. The eventual character was more similar to the Tenth Doctor than many other Doctors over the years had been to their predecessors — being also a young, romantic figure with a tendency to ramble and a lot of suppressed {{angst}} — but different enough to change the whole feel of the show. In particular, Smith's reinterpretation of the role took much more from Creator/PatrickTroughton's portrayal of the Doctor than any previous actor; most previous incarnations of the Doctor were made to directly contrast their immediate predecessor, and most portrayals of the role since 1982 were characterized in direct response to the popularity and omnipresence of Creator/TomBaker's incarnation.

* Really head-spinning example from ''Series/ThePaperChase'': When the study group is formed during the pilot episode, one woman is included. In the very second episode, that character's place in the study group, with no explanation, has been taken by another woman, Logan, who remains a major character throughout the series.

* In ''Series/OnceUponATimeInWonderland'', Anastasia the [[Literature/AliceThroughTheLookingGlass Red Queen]] is a suspiciously similar substitute for Cora[=/=]the [[GodSaveUsFromTheQueen Queen of Hearts]], who was KilledOffForReal in Season 3 of ''SeriesOnceUponATime'' and not available to play her traditional role as the BigBad of an ''Literature/AliceInWonderland'' adaptation. This is [[JustifiedTrope justified]] when it's revealed that Anastasia had deliberately modelled herself on Cora.

** Lampshaded: Al, the elderly man who sat at the opposite corner of the bar from Norm and occasionally made sarcastic comments, was gradually replaced by Phil, the elderly man who sat at the opposite corner of the bar from Norm and occasionally made sarcastic comments. In the ReunionShow episode of ''Series/{{Frasier}}'', Frasier says how good it is to see Al again, only to be told "[[LampshadeHanging I'm Phil, you jackass! Al died!]]"

* Done by necessity quite a lot on gentle old dears' British comedy ''Series/LastOfTheSummerWine'', as elderly cast members die off with inconvenient regularity. (The last member of the original regular cast, Peter Sallis, died in 2017 at the age of ninety-six, seven years after the show was finally cancelled.)

*** Chekov started out as a suspiciously similar substitute of Sulu, due to Creator/GeorgeTakei's [[AbsenteeActor absence during much of season 2]], before attaining his own niche as a character.

** The characters of TOS were based on the characters originally conceived for the rejected pilot, with Pike becoming Kirk, Boyce becoming Bones, Smith becoming Rand, etc.. This practice is extremely commonplace when a Pilot turns into a green-lighted series. Similarly, the characters of TNG were based on the characters of the abandoned "Star Trek: Phase II" series: Will Decker became the similarly-named Will Riker; Decker's old flame, the empathic Deltan Ilia, became Riker's old flame, the empathic Betazed Troi; and Xon, the Vulcan struggling to understand humanity, became Data, the android struggling to understand humanity. A writer's strike proved to be nothing more than a minor inconvenience for TNG: they just dusted off some old "Phase II" scripts and went to work (though only one script ended up being used for the strike-shortened second season; another was pushed back to season four).
** Following the success of TNG, a pattern began to emerge in the crew's makeup. There will always be an overeager, wet behind the ears kid for the young audience to relate to (see Wesley Crusher, Jake Sisko, Naomi Wildman); an inexperienced recruit (Dr. Bashir, Harry Kim, Travis Mayweather); a comic relief hustler with gross alien habits (see Quark, Neelix, and Dr. Phlox). Sometimes the characters were just obvious stand-ins for a more famous predecessor: Tuvok, the gruff, socially-awkward Vulcan security officer, was substituted for Worf, the gruff, socially awkward Klingon security officer for instance.
** For one season of ''Series/StarTrekTheNextGeneration'', Dr. Kate Pulaski (played by Creator/DianaMuldaur, who'd appeared twice as different characters in the [[Series/StarTrekTheOriginalSeries Original Series]]) replaced Dr. Beverly Crusher as ship's doctor. Pulaski was ''doubly'' a Suspiciously Similar Substitute since her abrasive tics were explicitly based on Bones [=McCoy=].

** In the early production of ''Series/StarTrekDeepSpaceNine'', Kira Nerys was actually a replacement character for Ro Laren, because the actress that played Ro in ''Series/StarTrekTheNextGeneration'' declined the offer to appear in ''Deep Space Nine''. The trope was mostly averted as Kira was developed into a very different character than Ro; most notably, Kira wasn't a Starfleet officer and as such related to those who were differently, especially in the beginning.
** The exact same thing happened in the early production of ''Series/StarTrekVoyager'': B'Elanna Torres was also a replacement character for Ro Laren because Michelle Forbes again refused to commit to a seven-year show.

** The original plans for Season 7 had Zoe as the Third Doctor's companion; soon the producer decided she should be written out as part of the show's heavy {{Retool}} and so they created Liz, a similar scientist, to replace her.

** The Nestene Consciousness which debuted in "[[Recap/DoctorWhoS7E1SpearheadFromSpace Spearhead from Space]]" is one to the Great Intelligence of the Troughton Era. Both are (mostly) disembodied gestalts seeking to conquer Earth who rely on partly disguised robotic servants to operate, but the Nestenes use animated plastic dummies instead of robot yeti.

** [[FacialHorror Facially deformed]] time-travelling DiabolicalMastermind Magnus Greel in "[[Recap/DoctorWhoS14E6TheTalonsOfWengChiang The Talons of Weng-Chiang]]" was originally supposed to be the facially-deformed incarnation of the Master from "[[Recap/DoctorWhoS14E3TheDeadlyAssassin The Deadly Assassin]]", as the story was planned as a direct sequel to it and was even written by [[Creator/RobertHolmes the same man]]. Due to its close proximity to ''that'' serial, however, it ended up mutating into something else. Remnants of that idea include both being hammy, vampiric serial killers on the run with a time machine, dying, and desperately looking for a way to cheat death. Magnus even talks about "regeneration" a few times.

** The Toclafane — mutated, insane, OmnicidalManiac humanoids dependent on [[LittleGreenManInACan heavily-armed miniature tank cases]] to survive — were created as a substitute for the Daleks if [[CaptainErsatz the revival show could not get the rights to use them]], as the negotiations with Terry Nation's estate were going badly. "[[Recap/DoctorWhoS27E6Dalek Dalek]]" (titled "Absence of the Daleks") would have revolved around the audience expecting to find a Dalek, but the creature instead being the last Toclafane, the race that wiped out the Time Lords. "[[Recap/DoctorWhoS27E12BadWolf Bad Wolf]]" and "[[Recap/DoctorWhoS27E13ThePartingOfTheWays The Parting of the Ways]]" would have been the conclusion of their StoryArc and revealed that they were in fact humans from the future. The final version of Series 1 did use Daleks in this role, but the Daleks encountered in that story were built from mutated humans like the Toclafane; while somewhat left-field to a viewer starting with Series 1, the twist is [[Recap/DoctorWhoS22E6RevelationOfTheDaleks not without precedent]] in the Classic Series. The Toclofane later showed up in Series 3, with their plot twist still making it into the series but in an even dourer context.
** Howard Attfield, who played Donna Noble's father in "[[Recap/DoctorWho2006CSTheRunawayBride The Runaway Bride]]", died during the filming of Series 4, having just finished his scenes for "[[Recap/DoctorWhoS30E1PartnersInCrime Partners in Crime]]". Rather than leave his one appearance there as-is and try to skirt around his absence for the rest of the season, the producers decided to have his scenes reshot with Wilfred Mott (Creator/BernardCribbins), who had been created as a one-off guest character in "[[Recap/DoctorWho2007CSVoyageOfTheDamned Voyage of the Damned]]" and was promptly retconned as Donna's maternal grandfather.
*** This was not the first time Cribbins played a ''Series/DoctorWho'' Suspiciously Similar Substitute; in the second of the 1960s non-canon movies, ''Film/DaleksInvasionEarth2150AD'', he plays Special Constable Tom Campbell, who replaces the movieverse version of Ian Chesterton who appeared in the earlier movie ''Film/DrWhoAndTheDaleks''. In the same film, Louise, the Doctor's niece, is introduced as an almost identical replacement for movieverse Barbara.

** [[Recap/DoctorWhoS31E7AmysChoice "Amy's Choice"]]: Some people have wondered if the Dream Lord, an EnemyWithout of the Doctor, is one for the Valeyard, villain of season 23's "The Trial of a Time Lord" arc.
** River Song is one to Captain Jack Harkness. Both are reoccurring on-off companions who the Doctor has difficulty trusting, both are time travelers much like the Doctor and have used vortex manipulators, and both are paradoxical in nature (much like the Doctor). Captain Jack is immortal and is a living fixed point-in-time, while River is a [[HalfHumanHybrid half-Time Lord]] whose entire life is a StableTimeLoop. The names they are usually known by are both aliases, and both of them are {{Anti Hero}}es in their early (chronological) appearances before reforming after spending time with the Doctor, and both are ExtremeOmnisexual and have dated members of various species and genders.

** TheChick in the FiveManBand started out as Cinnamon, who was replaced by a parade of guest stars in Season 4, Dana in Season 5, and Casey in Seasons 6-7 (with Mimi briefly serving as a TemporarySubstitute). Averted somewhat with Casey, who was not just the femme fatale but also replaced Rollin and Paris as the team's makeup master, since budget cuts required reducing the cast size. The show also attempted to replace Willy with a doctor named Doug, but Willy was SavedByTheFans.