Sometime after the banishment of King Bowser Koopa, the Koopalings and their minions, Princess Toadstool, Mario and Luigi went on vacation to the Dinosaur World, only for Princess Toadstool to be kidnapped by King Koopa and his minions. After adventuring and befriending Yoshi, Mario and Luigi managed to rescue Princess Toadstool from King Koopa's Neon Castle and subsequently decided to stay in Dinosaur Land's Dome City with the cave-people.
Several episodes of Super Mario World often had Mario, Luigi, Yoshi, Princess Toadstool, and occasionally Oogtar, a show-exclusive character, trying to stop the schemes of King Koopa and the Koopalings, as well as other villains such as Wizenheimer or the DinoRiders. Toad, who appeared in The Super Mario Bros. Super Show and The Adventures of Super Mario Bros. 3, does not appear in the series (nor did he appear in the game it was based on), making it the only Mario cartoon where he does not appear. Mario, Luigi, Princess Toadstool, King Koopa, and the Koopalings retain their designs from The Adventures of Super Mario Bros. 3, although the "L" on Luigi's cap is black instead of green in early episodes, Princess Toadstool has lighter skin and blue eyes instead of black eyes, and Cheatsy's hair is yellow/white instead of light blue. Also, Mario and Luigi's fire forms in the show are based on their fire from sprites from the game. Walker Boone, Tony Rosato, Tracey Moore and Harvey Atkin reprised their roles as Mario, Luigi, Princess Toadstool and King Koopa in the show.
Some episodes of Super Mario World can also be seen as social commentary for controversial issues, such as street gangs ("Born to Ride"), addiction ("Rock TV"), bullying in school ("A Little Learning") and obesity ("King Scoopa Koopa").
The show also had several episodes, such as "The Wheel Thing" and "Party Line", dealing with the introduction and consequences of introducing new concepts and technologies to others without thinking ahead, in this case, the cave-people of Dome City.
- Walker Boone — Mario
- Tony Rosato — Luigi
- Tracey Moore — Princess Toadstool
- Andrew Sabiston — Yoshi
- Harvey Atkin — King Bowser Koopa
- Tara Strong — Hip, Hop
- John Stocker — Oogtar, Koopa Wizard, Monty Moles, Koopa Football Players, Wizenheimer
- Paulina Gillis — Kootie Pie Koopa
- James Rankin — Cheatsy Koopa
- Dan Hennessey — Bully Koopa, Green Dinosaur, Purple Dinosaur, Rockman
- Michael Stark — Kooky von Koopa
- Gordon Masten — Big Mouth Koopa
- Judy Marshak — (Additional Voices)
- Catherine Gallant — (Additional Voices)
- Stuart Stone — (Additional Voices)