The character selection out of each game has been back and forth, so here's a list of all the characters ever playable, and which games they appeared in. The list will order the characters by their first appearance in the series. Exceptions will be listed in parentheses.
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!Introduced in:

!!''VideoGame/SuperMarioKart''
* Bowser
* Donkey Kong Jr. (Has never appeared in any other game, possibly because ''VideoGame/DonkeyKongCountry'' was released after this game and Nintendo decided to use Donkey Kong afterwards instead.) [[note]]However, there is speculation that Donkey Kong Jr. ''grew up'' into the Donkey Kong we know today and the Donkey Kong from the [[VideoGame/DonkeyKong 1980 arcade game]] is Cranky Kong today.[[/note]]
* Koopa Troopa (Has also appeared in ''Double Dash!!'', ''Wii'', ''7'', and ''8''.)
* Luigi
* Mario
* Peach (Referred to as "Princess" in ''Super Mario Kart'' only.)
* Toad
* Yoshi

!!''VideoGame/MarioKart64''
* Donkey Kong
* Wario

!!''VideoGame/MarioKartSuperCircuit''
No new characters, the roster is the same as ''Mario Kart 64''.

!!''VideoGame/MarioKartDoubleDash''
* Baby Luigi (Has also appeared in ''Wii'' and ''8''.)
* Baby Mario (Has also appeared in ''Wii'' and ''8''.)
* Birdo (Has also appeared in ''Wii''.)
* Bowser Jr. (Has also appeared in ''Wii'' and ''Arcade GP DX''.)
* Daisy (Has also appeared in ''DS'', ''Wii'', ''7'', and ''8''.)
* Diddy Kong: (Has also appeared in ''Wii''.)
* King Boo (Has also appeared in ''Wii''.)
* Paratroopa (Has not appeared in any other game.)
* Petey Piranha (Has not appeared in any other game.)
* Toadette (First appearance ever, has also appeared in ''Wii'' and ''8''.)
* Waluigi (Has also appeared in ''DS'', ''Arcade GP 2'', ''Wii'', ''Arcade GP DX'', and ''8''.)

!!''VideoGame/MarioKartArcadeGP''
* [[VideoGame/PacMan Blinky]] (Has also appeared in ''Arcade GP 2''.)
* [[VideoGame/PacMan Ms. Pac Man]] (Has also appeared in ''Arcade GP 2''.)
* VideoGame/PacMan: (Has also appeared in ''Arcade GP 2'' and ''Arcade GP DX''.)

!!''VideoGame/MarioKartDS''
* Dry Bones (Has also appeared in ''Wii''.)
* [[NintendoEntertainmentSystem R.O.B.]] (Has not appeared in any other game.)
* Shy Guy (In ''DS'', he is only playable through DS download-play. He has also appeared in ''7'' and ''8''.)

!!''VideoGame/MarioKartArcadeGP2''
* [[VideoGame/{{Tamagotchi}} Mametchi]] (Has not appeared in any other game.)

!!''VideoGame/MarioKartWii''
* Baby Daisy (First appearance ever, has also appeared in ''8''.)
* Baby Peach (Has also appeared in ''8''.)
* Dry Bowser (In ''8'', he is a DLC character. Has also appeared in ''Arcade GP DX''.)
* Funky Kong (Has not appeared in any other game.)
* UsefulNotes/{{Mii}} (Has also appeared in ''7'' and ''8''.)
* Rosalina (In ''Arcade GP DX'', she is a DLC character.)

!!''VideoGame/MarioKart7''
* Lakitu (Has also appeared in ''8''.)
* Metal Mario (In ''Arcade GP DX'', he is a DLC character.)
* [[VideoGame/SuperMarioGalaxy Queen Bee]] (Referred to as "Honey Queen" in ''7''. She has not appeared in any other game.)
* Wiggler (Has not appeared in any other game.)

!!''[[http://www.mariowiki.com/Mario_Kart_Arcade_GP_DX Mario Kart Arcade GP DX]]''
* [[VideoGame/TaikoDrumMaster Don-chan]] (Has not appeared in any other game.)

!!''VideoGame/MarioKart8''
* Baby Rosalina (First appearance ever)
* Iggy Koopa
* Larry Koopa
* Lemmy Koopa
* Ludwig Von Koopa
* Morton Koopa Jr.
* Pink Gold Peach (First appearance ever)
* Roy Koopa
* Wendy O. Koopa
* [[Franchise/TheLegendOfZelda Link]] (DLC character, in his ''[[VideoGame/TheLegendOfZeldaSkywardSword Skyward Sword]]'' appearance)
* [[VideoGame/AnimalCrossing Villager]] (DLC character, in his ''New Leaf'' appearance opposite to ''VideoGame/SuperSmashBros'')
* [[VideoGame/AnimalCrossing Isabelle]] (DLC character)
* [[VideoGame/SuperMario3DWorld Cat Peach]] (DLC character)
* [[VideoGame/SuperMario3DLand Tanooki Mario]] (DLC character)
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