!!Listed Trivia:

* AccidentallyAccurate: In "Tomorrow Is Yesterday" the ''Enterprise'' travels back in time to the 1960s. It's mentioned that three astronauts are taking part in a manned moon shot on Wednesday. Two years after the episode aired, Apollo 11 blasted off on July 16, 1969 (a Wednesday) carrying three astronauts (Neil Armstrong, Buzz Aldrin, and Michael Collins). Given that the Apollo program was already getting started around the time of this episode, however, it was [[ShownTheirWork already known that there would be three astronauts per spacecraft]], and odds were good that at least ''one'' of the craft bound for the moon would launch on a Wednesday. That the Wednesday launch happened to be Apollo 11 (the first moon landing) was a happy coincidence.
* ActingForTwo:
** Shatner plays both Kirk and sinister-impostor-Kirk in "[[Recap/StarTrekS1E5TheEnemyWithin The Enemy Within]]" (transporter accident), "[[Recap/StarTrekS1E7WhatAreLittleGirlsMadeOf What Are Little Girls Made Of?]]" (robot double), "[[Recap/StarTrekS2E4MirrorMirror Mirror, Mirror]]" (mirror universe), "[[Recap/StarTrekS3E24TurnaboutIntruder Turnabout Intruder]]" (body swap), and ''Film/StarTrekVITheUndiscoveredCountry'' (alien shapeshifter).
** Shatner also does brief double duty in "[[Recap/StarTrekS1E29OperationAnnihilate Operation -- Annihilate!]]", in the scene where Kirk discovers the body of his brother Sam.
* BannedInChina: The first BBC broadcast of "Miri" led to protests over its allegedly over-horrific nature (since it involved children in peril and adults getting killed), and as a result it and three later episodes -- "Plato's Stepchildren", "The Empath" and "Whom Gods Destroy" -- were suppressed from BBC broadcasts of the show until the 1990s due to being considered excessively violent and horrific.
* {{Blooper}}: In "The Enemy Within", the scratches on Evil Kirk's face change side during his VillainousBreakdown near the end.
* CreatorBacklash:
** Creator/HarlanEllison's opinion of "The City On The Edge Of Forever" is in the Creator Backlash Hall Of Fame.
** Grace Lee Whitney had some choice words about the episode "The Enemy Within" later on:
-->"At the end of "The Enemy Within," there is a badly botched attempt at humor. In a poorly motivated and out of character moment, Mr. Spock needles me about my feelings towards the evil Kirk (who came to be called "the Imposter," even though he was supposedly every bit as much a part of the "real" James T. Kirk as the good Kirk). There is almost a nasty leer on Spock's face as he says to me, "The Imposter had some very interesting qualities, wouldn't you say, yeoman?" My response was to ignore the jibe. I can't imagine any more cruel and insensitive comment a man (or Vulcan) could make to a woman who has just been through a sexual assault! But then, some men really do think that women want to be raped. So the writer of the script (ostensibly Richard Matheson - although the line could have been added by Gene Roddenberry or an assistant scribe) gives us a leering Mr. Spock who suggests that Yeoman Rand enjoyed being raped and found the evil Kirk attractive!"
* CreatorCameo: Gene Roddenberry himself voiced the ship's cook in "Charlie X".
* DawsonCasting:
** Robert Walker was 26 years old when he played 17-year-old Charlie Evans in "Charlie X".
** Michael J. Pollard (27 years old) and Kim Darby (19) play pre-pubescent children in "Miri".
* ExecutiveMeddling:
** The network chiefs felt the initial pilot episode, "The Cage", was [[ViewersAreMorons too cerebral for the average viewer at home]], and turned it down on those grounds. [[NetworkToTheRescue They gave the series another chance]] though, on the proviso that Gene Roddenberry gave them something with a bit more action and a bit less philosophy.
** The original script for "The Alternative Factor" had a subplot about a romance between Lazarus and Lieutenant Masters. It was cut when network heads objected due to the actress playing Masters being black. The hasty rewrites that followed were one cause of the uneven story we ended up with.
* FakeNationality:
** William Shatner and James Doohan (both Canadians) play an American and a Scotsman, respectively. Creator/CraigFerguson vowed revenge on James Doohan as a teenager and would go on to play a [[IAmVeryBritish grossly-exaggerated Englishman]] on ''Series/TheDrewCareyShow'' just to spite ''Star Trek'' casting directors.
** Walter Koenig is a partial case: his parents were Russian Jews but Koenig himself was an American citizen playing the Russian Chekov.
** Nichelle Nichols (an American) played Uhura, whose native language is established as Swahili, implying Uhura is from somewhere in eastern Africa.
** In the episode "Space Seed", Khan Noonien Singh is an Indian Sikh, played by Mexican actor Ricardo Montalban.
* FanNickname: The (unnamed) alien in "The Man Trap" is almost universally known as "the salt vampire".
* GeorgeLucasAlteredVersion: The 40th anniversary "Remastered" versions (also known as TOS-R), which (contentiously) replace the original practical effects (mostly involving ships, planets and [[AlienSky their skies]], and phasers) with CGI.
* HeyItsThatGuy:
** Lt. Cdr. Gary Mitchell in the second pilot "Where No Man Has Gone Before" is played by Gary Lockwood, who also played Dr. Frank Poole in 2001: A Space Odyssey. No wonder HAL wasn't too happy with him...
** The android servant in "What Are Little Girls Made Of?" is Lurch from ''Series/TheAddamsFamily''. He also voices Balok in "The Corbomite Maneuver".
** In "Miri", Miri is Mattie from ''Film/TrueGrit'', the "Bonk Bonk" boy is Dill from ''Film/ToKillAMockingbird'', and Jahn is C.W. Moss from ''Film/BonnieAndClyde''.
** Sarek is the Romulan Commander? No wonder Spock has daddy issues...
** [[Series/BattlestarGalacticaClassic Count Baltar]] is a Klingon commander!
** One for film music fans - Creator/BasilPoledouris never wrote any music for ''Star Trek'' but he turns up as an extra in some episodes (like "Obsession").
* HeyItsThatVoice:
** Majel Barret did her best Creator/MaeWest impression when voicing the malfunctioning computer in "Tomorrow Is Yesterday". She would use that seductive purr again when voicing M'Ress in ''WesternAnimation/StarTrekTheAnimatedSeries''.
** [[Disney/TheJungleBook One of the wolves who raised Mowgli]] is head of the Organian council!
** In the Japanese dub:
*** Kirk is voiced by Masaaki Yajima, who voiced [[GiantRobo Dr. Kusama]] and [[ShinMazinger Zeus]].
*** Scott is voiced by the late Osamu Kobayashi and later by Creator/KenjiUtsumi ([[FistOfTheNorthStar Raoh]])
* HeyItsThatSound:
** The [[http://www.youtube.com/watch?v=gASm1AMYGHk transporter sound effect]] was based on [[http://www.youtube.com/watch?v=k0hs4KrkFp8#t=0m30s part of the "Tardis taking off" sound effect]] in ''Series/DoctorWho''.
** The [[https://www.youtube.com/watch?v=34FsrucOOBY sound effect for the photon torpedoes firing]] was taken from [[https://www.youtube.com/watch?v=QUY1KYEABz0 the green disintegrator rays]] in ''Film/TheWarOfTheWorlds''.
* LifeImitatesArt: This show inspired so many things...
** Possibly its ultimate triumph was that Nichelle Nichols's role on the show was the inspiration for Dr. Mae Jemison, ''America's first female African-American astronaut'', who later did a cameo on ''Series/StarTrekTheNextGeneration''.
** It inspired the Bluetooth headset.
** The show is often credited as the inspiration for cell phones, but it also accurately predicted the tablet PC.
** The military and many high-level police agencies are experimenting with non-lethal heat and sound beams to disperse riots and disarm attackers without killing them. Phasers on Stun, anyone?
** The show may not have been the first inspiration for automatically opening doors, but it sure lit the fire under more than a few engineers, with practical models appearing within a decade.
* NamesTheSame: The staff got in a bit of trouble due to similarity of the episode "Arena" to a short story of the same name they hadn't been aware of. The threat of a copyright lawsuit was settled by giving a credit to its author, Creator/FredricBrown.
* NoBudget:
** In order to cut costs, incidental music avoided scoring anything for violins. Melodies in the strings are played by violas. Violinists charge that much more, apparently.
** Also, [[StockFootage space and bridge scenes are recycled over and over]], and a few props and sets are recycled into later episodes.
* TheOtherDarrin: Shatner's predecessor, Jeffery Hunter, played Captain Pike in "The Cage". This footage was later re-used in "The Menagerie", with Pike himself appearing a motionless deformity in an iron lung-type device. This was primarily to disguise the fact that Hunter was unavailable; this new Pike was played by a lookalike (such as he is) named Sean Kenney. What's interesting is that Captain Pike was retconned into Kirk's predecessor, as well; He was the original Captain of the ''Enterprise'', with Mr. Spock as his science officer. This is still canon in the Abrams film, in which Bruce Greenwood plays Pike.
* ThePeteBest: Jeffrey Hunter's Captain Christopher Pike has gained something of a loyal following as being "the ''Star Trek'' captain who wasn't". Adventures featuring him have appeared in the expanded universe, in novels and in comic books; and he also made an reappearance in [[Film/StarTrek the 2009 reboot movie]], as played by Bruce Greenwood.
* RealitySubtext: Scotty's refusal to lower the shields against orders in "A Taste of Armageddon" is based on an actual story from James Doohan's military service.
* RealLifeRelative: Many of the Onlies in "Miri" are children of various members of the cast and crew. The little girl Kirk picks up is played by William Shatner's daughter, Melanie Shatner.
* RecycledSet: The same backlot is used as 1930s New York in "The City on the Edge of Forever", a Space Amish town in "The Return of the Archons", and a planet that coincidentally looks exactly like 1960s Earth in "Miri". (It's actually the same backlot used as Mayberry in ''Series/TheAndyGriffithShow''; Kirk and Edith even walk past "Floyd's Barber Shop".)
* RedShirt: Although the TropeNamer, the first red-shirted casualty doesn't appear in series until episode 7 ("What Are Little Girls Made Of?"); the very first casualties are blue-shirted Science Team and gold-shirted Command squaddies.
* RetroactiveRecognition:
** [[Advertising/TheMostInterestingManInTheWorld I don't always play Redshirts, but when I do, I survive the whole episode.]] (Johnathan Goldsmith appears in "The Corbomite Maneuver.")
** Also in "The Corbomite Maneuver", Creator/ClintHoward is the real Balok.
** In "Tomorrow Is Yesterday", Captain Kirk is interrogated by... Captain Kirk! That's Officer Kirk from ''Series/HappyDays'' -- who, in a later ''Happy Days'' episode, was promoted to captain.
** Kirk's attorney in "Court Martial" is... [[Series/MagnumPI Ice Pick?]]
* UsefulNotes/TheRuralPurge: Inverted - it should be noted that the demographic information that led to the Rural Purge wasn't available from Neilsen before 1970 or so; had it been, ''Trek'' would've benefited since it attracted advertisers' favored demographics.
* ScienceMarchesOn:
** It's mentioned in "The Man Trap" that buffalo are extinct. It is true that overhunting brought the buffalo very close to extinction at the end of the nineteenth century. In the 1960s, it was a fairly reasonable assumption that buffalo might be extinct in the future, although probably not the best guess since conservation efforts had started decades earlier. Today they are no longer considered endangered at all. (The episode also mentions passenger pigeons, which were already extinct when the episode was made.)
** In "Tomorrow Is Yesterday" the ship is thrown back in time by an encounter with a "black star". At the time, there was no widely-accepted term for a star which had collapsed into a singularity and had gravity so strong light could not escape, which we now call a "black hole". The term "black hole" was not generally accepted until later in 1967.
** In one episode, Spock rightly points out that "evolution is man evolving from apes" is a grossly misleading and deliberate mischaracterization--but describes evolution as life forms [[EvolutionaryLevels evolving from "lower" to "advanced" stages]]. Now, evolution is understood as life forms changing over time to suit their environment. While they ''usually'' become more complex than their ancestors, they do sometimes become less complex if losing a trait 1. makes them more successful in their environment or 2. doesn't hurt them either way.
* SerendipityWritesThePlot:
** The transporter was created because it would be too expensive to have the crew land on the planets in a shuttle every episode.
** During production of "Where No Man Has Gone Before", Gary Lockwood found the silver contact lenses painful and difficult to see through. Gary Mitchell's imperious stare is a result of Lockwood having to look down his nose through the pinholes in the lenses.
* TechnologyMarchesOn:
** That big ass tape deck that Kirk uses to record his CaptainsLog on, as seen in "Dagger of the Mind".
** "The Menagerie", in depicting Pike's condition, severely underestimated how far computer-assisted communication would come in just a few decades (think Stephen Hawking).
** In "The Conscience of the King", Kodos faked his own death with a body "burned beyond recognition" and started again with a new identity. Since the episode first aired, several technologies have become commonplace (such as DNA matching) that would have made the question of identification less difficult for the heroes.
*** Unless of course the body was disfigured by chemicals or radiation that degraded the DNA making it unidentifiable.
** In "Balance of Terror", Spock removes a panel to reveal that some internal electronics have caught fire. (And then he puts the fire out with his hands. Love that Vulcan stoicism.) It seems unlikely that an interstellar spaceship wouldn't have an over current protection device that would prevent such a fire.
* ThrowItIn:
** The Vulcan mind-meld, neck pinch and salute are all examples of this. All were suggestions made by Creator/LeonardNimoy. In the case of the first two, they replaced more mundane, conventional ideas in the original scripts (respectively, a simple interrogation in "Dagger of the Mind", and Spock slugging evil Kirk with a pistol butt in "The Enemy Within").
** In "The Naked Time", Uhura's response to being cast as the "fair maiden" in Sulu's swashbuckling fantasy ("Sorry, neither.") was an ad lib by Nichelle Nichols during rehearsals.
** The entire scene in "The Naked Time" where Spock struggles to remain in control of his emotions was suggested by Leonard Nimoy, and they only had time for one take, which was entirely improvised.
** According to legend, the stagehands didn't like Shatner very much, so in the episode "The Trouble With Tribbles," they continued the avalanche of tribbles much longer than was scripted (including the final tribble that bounces off his head at the end). Shatner can clearly be seen glancing up at the prop men with annoyance.
* TroubledProduction: Part of the reason "The Alternative Factor" is so bad is that the intended guest star, John Drew Barrymore, the most notoriously flaky member of that family, suddenly disappeared shortly before shooting and Robert Brown had to replace him at literally the last minute.
* VindicatedByReruns: Possibly the TropeCodifier. It was a modest ratings success until Creator/{{NBC}} developed the habit of [[ScrewedByTheNetwork switching its timeslot around]]. The [[ExecutiveMeddling extensive rewriting of scripts]] and lack of immediate success made many of its more talented writers leave, which caused [[SeasonalRot the quality to slip noticeably in a short time]]. It was canceled after the second season, but quickly UnCanceled following an extensive letter-writing campaign from its fans. The third season saw even worse ratings, and NBC canceled it for real. Shortly afterwards, American television industry discovered the use of {{demographics}}. When stations noticed that, according to the new standards of how ratings were calculated, ''Star Trek'' should have been one of the most successful shows on TV (and that NBC had killed what could have been their golden goose), they were rushing to throw on ''Star Trek'' reruns to attract the young demographic that it had been popular with. It didn't take many years of reruns before the show's modest fanbase grew into a force to be reckoned with. The rest is history.
* WhatCouldHaveBeen:
** The entire series could have been very different if the network executives hadn't declined the first pilot.
** "The Naked Time" and "Tomorrow Is Yesterday" were originally conceived as a two-part story, which is why the former ends with an out-of-the-blue time-travel incident that leads nowhere and the latter begins with the ''Enterprise'' already back in time due to (in the aired episode) an unrelated time-travel incident.
** Harlan Ellison's script for "The City at the Edge of Forever" was heavily altered to fit the tone of the series (as well as to trim a large cast and settings that were far beyond the show's budget). Rather than [=McCoy=], the past was changed by an evil drug-dealing crewman who ends up in a particularly hellish AndIMustScream situation trapped inside a newborn star. Also, Kirk is frozen with indecision over whether to let Edith die, forcing Spock to step in. The general consensus from those who've read it is that it would make a great standalone story, but as an episode of ''Trek'' it just feels wrong.
** The episode "Spectre of the Gun" (the one set at the O.K. Corral) was originally planned to be filmed on an existing Western town set on the backlot. However, serious budget cuts for the series' third season made this impossible. So, it was instead made on a soundstage in a surreal, incomplete, plainly artificial environment. Though some (including Creator/LeonardNimoy) were skeptical over this move, it's now largely viewed to have been a good choice for the story.
** James Hong (a.k.a. [[Film/BigTroubleInLittleChina David Lo Pan]]) auditioned for Sulu, but was passed over in favor of George Takei.
** Creator/JamesDoohan had tried several different accents as Scotty before settling on a Scottish accent.
* WordOfGay: Inverted. Since Creator/GeorgeTakei has come out of the closet, many have speculated that Sulu is gay too, but Takei asserted that Sulu [[TimeTravelTenseTrouble was/is/will be]] straight.
* YouLookFamiliar: After appearing under heavy prosthetic make-up in "The Menagerie", Sean Kenney would later appear as a bridge crewmember in "Arena" and "A Taste of Armageddon".

!!This series is the TropeNamer for:

* AirVentPassageway
* BeamMeUpScotty
* BeardOfEvil
* BoldlyComing
* CaptainsLog
* FascinatingEyebrow
* All three components of the FreudianTrio:
** TheKirk
** TheSpock
** TheMcCoy
* GreenSkinnedSpaceBabe
* HesDeadJim
* ImADoctorNotAPlaceholder
* KirksRock
* KirkSummation
** ShutUpKirk
* MarySue: From ''Fanfic/ATrekkiesTale''.
* MirrorUniverse
* RedShirt
** MauveShirt
** RedShirtArmy
* ScottyTime
* SpaceWhaleAesop: From ''Film/StarTrekIVTheVoyageHome''.
* SpockSpeak
* StrawVulcan
* TheissTitillationTheory: Named for the show's costume designer, William Ware Theiss.
* VulcanHasNoMoon
* WagonTrainToTheStars
* WeComeInPeaceShootToKill: From "[[FilkSong Star Trekkin']]".
* WhereNoParodyHasGoneBefore: Shares its name with the title of the fourth season episode of ''{{Futurama}}'', whose plot was an homage to and an AffectionateParody of everything ''Franchise/StarTrek'', particularly the original series and its movies.

!! This series [[ImageSource provides the page image]] for:

* ChekovsGun
* CosmeticallyAdvancedPrequel (top half)
* TheEmpire
* EnergyBeings
* EverythingSensor
* EvolutionaryRetcon (left half)
* ExplosiveInstrumentation
* FreudianTrio
* HistoricalDomainCharacter (bottom-left)
* TheKirk
* TheMcCoy
* PlanetOfHats
* PressurePoint
* ProudScholarRaceGuy
* RedShirt
* RedShirtArmy
* SciFiWritersHaveNoSenseOfScale
* SocialSemiCircle
* TheSpock
* TeleportersAndTransporters (fan-art)
* TeleporterAccident
* TheissTitillationTheory

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