!!Quinn Mallory (Jerry O'Connell)

%%* {{Adorkable}}
%%* {{Badass}}
%%** BadassBookworm
%%** TookALevelInBadass
* BasementDweller: He still lived with his mother while finishing college. He still had his own room, but converted his basement into a makeshift laboratory and spent most of his free time down there.
* BrilliantButLazy: In the pilot, he passes up the chance to correctly answer a difficult question (despite Arturo yelling at him) because it didn't interest him. On the other hand, he took the time to read Arturo's papers that weren't assigned for class because their contents did.
%%* ButtMonkey
* ChildProdigy: Was skipped ahead two grades when he was eleven.
%%* ChronicHeroSyndrome
* DidntSeeThatComing: He was originally trying to invent anti-gravity, but accidentally created a wormhole instead.
* DisappearedDad: Michael Mallory died in an automobile accident when Quinn was very young.
* {{Fanservice}}: The show frequently has Quinn [[ShirtlessScene shirtless]].
%%* GadgeteerGenius
* HeterosexualLifePartners: With Rembrandt.
%%* HollywoodNerd
%%* HonorBeforeReason
* IJustWantToBeNormal: He resented his intelligence for years because it made him different from everyone else. (Being skipped ahead and thus smaller than his classmates didn't help.)
* MeaningfulName: ''Quinn'' is Irish for "wisdom, reason, intelligence" and ''Mallory'' means "unlucky." Pretty fitting for a smart guy who [[spoiler:ends up being merged with his AlternateUniverse duplicate]].
* TheNthDoctor: Played by Jerry O'Connell for the first four seasons, [[spoiler:then briefly by an unknown actor in the Season 5 premiere before being replaced by Mallory]].
* ReallyGetsAround: Had {{Ship Tease}}s with Wade and Maggie, as well as plenty of [[GirlOfTheWeek one-off love interests]].
* TeamDad: Becomes this after Arturo dies in late Season 3. {{Lampshaded}} in "Slither," where Quinn laments that, without Arturo, "It's all on me, and I'm flying blind."
%%* TeenGenius
%%* TwoFirstNames

!!Wade Welles (Sabrina Lloyd)

* AlliterativeName: '''W'''ade '''W'''elles.
* BackForTheDead: [[spoiler:In "Requiem."]]
* BreakTheCutie: Three years of sliding takes a toll on her; Arturo's death is the moment that finally breaks her.
-->You know, when I first started sliding, all I saw was adventure. Now all I seem to see is death.
* DevotedToYou: EVERY male character in EVERY dimension falls in love with her.
%%* DistressedDamsel
%%* [[DroppedABridgeOnHim Dropped A Bridge On Her]]
%%* TheHeart
%%* HeroicSacrifice
%%* GenderBlenderName
%%* HollywoodNerd
* HonorBeforeReason: Frequently, much to the others' occasional irritation.
* PlatonicLifePartners: With Rembrandt.
* SpellMyNameWithAnS: "Welles" or "Wells."
** WordOfGod admitted to inconsistency within scripts, making it DependingOnTheWriter.
%%* TechnoWizard
* TomboyAndGirlyGirl: With Maggie in Season 3. Wade is the Girly Girl of the pair.
* WhyDidItHaveToBeSnakes: In "Rules of the Game," she says she has a problem with being on airplanes.
-->'''Quinn:''' [[LampshadeHanging Sliding between parallel worlds doesn't bother you, but flying does?]]\\
'''Wade:''' You have no idea how much.
** "The Dream Masters" reveals she was once robbed at knife-point, giving her a fear of knives and of being cut. She also has a problem with snakes, though apparently got over it by the time of "Slither."

!!Rembrandt Brown (Cleavant Derricks)

%%* AsTheGoodBookSays
* {{Badass}}: Seasons 4 and 5.
%%* BewareTheNiceOnes
* BlackBestFriend: To Quinn and later Wade and Maggie.
* BreakTheCutie: He spent ''months'' in a Kromagg prison.
%%* ButtMonkey
* ConspiracyTheorist: "The Return of Maggie Beckett" reveals that Remmy always believed aliens landed at Roswell.
%%* CrouchingMoronHiddenBadass
%%* DeadpanSnarker
* DirtyCoward: Season 1.
%%* TheEveryman
%%* TheHeart
* HeterosexualLifePartners: With Quinn.
* HiddenDepths: In "Eggheads," he recognizes a classical composer after hearing only a few seconds of a piece.
-->If you're gonna play the game, ya gotta appreciate the greats.
* ItsAllAboutMe: Prone to this a lot in Season 1. He gets over it, though.
* ManchurianAgent: [[spoiler:In Season 4.]]
* ManlyTears: His nickname is "Crying Man," after all.
* TheNicknamer: But only to the Mallory brothers--"Q-ball" (Quinn), "Farm Boy" (Colin) and "Fog boy" (Mallory).
* OddFriendship: With Arturo.
%%* OnlySaneMan
* PlatonicLifePartners: With Wade. Starting in Season 4, also with Maggie.
* RealMenCook: In "Paradise Lost," it's stated he was a cook while serving in the Navy.
* TedBaxter: He has a lot of these moments in the first two seasons.
* TeamDad: In Season 5.
* TookALevelInBadass: At the start of the series, he was easily spooked by dangers on parallel worlds. By Season 4, he gladly fights ''Kromaggs'' hand-to-hand and mocks them to their faces.
* WhyDidItHaveToBeSnakes: In "Slither," of snakes themselves.

!!Maximillian Arturo (Creator/JohnRhysDavies)

%%* AgentScully
%%* BadassGrandpa
* CatchPhrase: The number of times he called someone a "blistering idiot" and yelled "Incoming!" at the end of a slide borders on this.
%%* CoolOldGuy
* DeadpanSnarker: Tends to react to things around him with either blustering anger or dry sarcasm. One example from the pilot, where everyone's shock at finding themselves in a Soviet-dominated parallel America is interrupted by the Professor's desire for lunch:
-->'''Quinn:''' Professor, how can you ''eat'' at a time like this?!\\
'''Arturo:''' My stomach has no political preference.
* DisappearedDad: According to "Into the Mystic," he's actually this to someone back home.
%%* DroppedABridgeOnHim
* EveryoneCallsHimBarkeep: The others almost always address him as "Professor."
%%* HeroicSacrifice
* HiddenDepths: Lampshaded in "Eggheads," as he talks about his dead wife and how encountering her double is stirring old feelings.
-->'''Wade:''' I had no idea that you were such a romantic.\\
'''Arturo:''' And I had no idea that I would have the opportunity.
* IJustWantToBeSpecial: Season 2 introduced the idea that he resented Quinn for inventing sliding ''by accident''.
-->You resent the boy because it comes so easily to him.
* JerkWithAHeartOfGold: But virtually every single double encountered was a {{Jerkass}}.
* LastNameBasis: If the others don't address him as "Professor," then they do this.
* MissingMom: According to "Season's Greedings," his mother died during a WorldWarII bombing. [[spoiler:While WordOfGod confirms that the Arturo that said this was the double from "Post Traumatic Slide Syndrome," their two worlds were described as so similar that the real Arturo likely experienced similar events.]]
%%* MisterExposition
* OddFriendship: With Rembrandt.
* ParentalSubstitute: To Quinn.
%%* TheProfessor
* RedemptionEqualsDeath: [[spoiler:See SpotTheImposter below. The unscrupulous fake Arturo from "Post-Traumatic Slide Syndrome" ended up taking a bullet for Quinn.]]
* SecretlyDying: Introduced in "The Guardian," where Quinn finds out and is sworn to secrecy. Rembrandt would find out in "The Last of Eden."
* SoProudOfYou: He's not one to get emotional, but his admiration for Quinn always came through.
-->Every teacher goes through life hoping just once he'll have a student like you.
* SpotTheImposter: In "Post-Traumatic Slide Syndrome," the Sliders find themselves faced with two Arturoes each claiming to be theirs. The Sliders themselves have trouble figuring out who is who [[spoiler:and WordOfGod ultimately confirmed what fans long suspected: the wrong one slid with them]].
%%* TheSmartGuy
%%* TakingTheBullet
* TeamDad: Seasons 1-3.
%%* TechnicalPacifist
%%* TedBaxter

!!Maggie Beckett (Kari Wuhrer)

%%* ActionGirl
%%* CuteBruiser
* DaddyIssues: Highlighted in "The Return of Maggie Beckett."
%%* DeadpanSnarker
%%* DeadGuyJunior
%%* DefrostingIceQueen
%%* DistressedDamsel
* TheHeart: In Season 5.
%%* HiddenDepths
%%* {{Jerkass}}, later JerkWithAHeartOfGold
%%* MsFanservice
* MyFriendsAndZoidberg: Her joining the team late Season 3 wasn't exactly warmly embraced, especially by Wade. Rembrandt points this attitude out in "The Other Slide of Darkness."
* PlatonicLifePartners: With Rembrandt, starting in Season 4.
* SameCharacterButDifferent: Her personality was [[{{Retool}} retooled]] between Seasons 3 and 4. [[LampshadeHanging Lampshaded]] in the Season 4 premiere with a character with a personality of the Season 3 Maggie.
%%* TheSnarkKnight
* SuspiciouslySimilarSubstitute: Averted at first, as she was nothing like Arturo. Her Season 4 onward depiction does bear some similarity to Wade's, though.
* TeamMom: In Season 4-5.
* TomboyAndGirlyGirl: With Wade and later Diana. Maggie is the Tomboy of the pair.
%%* WaifFu

!!Colin Mallory (Charlie O'Connell)

%%* {{Adorkable}}
* DroppedABridgeOnHim: Possibly. See below.
%%* HollywoodNerd
* FishOutOfWater: After spending most his life living in an Amish paradise, he has a little trouble adapting to more advanced universes for a while.
* GadgeteerGenius: He built his own hang glider, for one.
* PutOnABusToHell: In "The Unstuck Man," Colin was made unstuck and left involuntarily sliding from one dimension to the next. At first, there was concern that Colin didn't survive, but he was generally treated as still alive and in need of help. By the end of the season, however, the characters acknowledged that Colin may really be dead, but it was nonetheless left ambiguous.
* SmarterThanYouLook: Colin is rather naive, but only because he came from a less advanced world. He is nonetheless quite intelligent, adapting rather well to modern technology and figuring things out for himself.
* WideEyedIdealist: As seen in "California Reich" and "My Brother's Keeper."
-->You don't hurt someone to help yourself...at least you're not supposed to.

!!Quinn "Mallory" Mallory (Robert Floyd)

* AppliedPhlebotinum: Geiger's experiments and combining him with Quinn allowed Mallory to walk again.
%%* BookDumb
* DarkAndTroubledPast: Including ParentalAbandonment, a criminal past and suffering from muscular dystrophy.
* FlipPersonality: Mallory emerged as the dominant personality, but in "The Unstuck Man" and "Applied Physics," Quinn's personality and memories periodically broke through. By the end of "New Gods for Old," however, Mallory could no longer feel Quinn.
* IOweYouMyLife: He is weary of Dr. Geiger, but acknowledges that without him, he'd still be in a wheelchair.
* LastNameBasis: Mainly because Maggie was incapable of calling him "Quinn," and then everybody picked it up. Even Diana, who knew him before Season 5's events.
%%* LoveableRogue
%%* TheNthDoctor
* ParentalAbandonment: His parents died when he was very young.
* SharingABody: With Quinn.
%%* SplitPersonality

!!Diana Davis (Tembi Locke)

* AlliterativeName: '''D'''iana '''D'''avis.
%%* BlackAndNerdy
* BreakTheCutie: Back-to-back episodes "Applied Physics" and "Strangers and Comrades."
* HeelFaceTurn: In the episode where she's introduced.
%%* HotScientist
%%* SuspiciouslySimilarSubstitute
* TomboyAndGirlyGirl: With Maggie. Diana is the Girly Girl of the pair, taking Wade's place in Season 5.