The Simpsons feature many episodes which are not considered to be official in The Simpsons timeline, and as such the information is regarded as non-canon. Any article about a character, place or object which only appears in these episodes, or sections in an article about these events, should have the {{Noncanon}} template added to it ({{Noncanon Episode}} if it's an episode). Below is a list of episodes, games and comics considered non-canon.
Episodes
Treehouse of Horror Series
- Treehouse of Horror
- Treehouse of Horror II
- Treehouse of Horror III
- Treehouse of Horror IV
- Treehouse of Horror V
- Treehouse of Horror VI
- Treehouse of Horror VII
- Treehouse of Horror VIII
- Treehouse of Horror IX
- Treehouse of Horror X
- Treehouse of Horror XI
- Treehouse of Horror XII
- Treehouse of Horror XIII
- Treehouse of Horror XIV
- Treehouse of Horror XV
- Treehouse of Horror XVI
- Treehouse of Horror XVII
- Treehouse of Horror XVIII
- Treehouse of Horror XIX
- Treehouse of Horror XX
- Treehouse of Horror XXI
- Treehouse of Horror XXII
- Treehouse of Horror XXIII
- Treehouse of Horror XXIV
- Treehouse of Horror XXV
- Treehouse of Horror XXVI
- Treehouse of Horror XXVII
- Treehouse of Horror XXVIII
- Treehouse of Horror XXIX
- Treehouse of Horror XXX
- Treehouse of Horror XXXI
- Treehouse of Horror XXXII
- Treehouse of Horror XXXIII
- Treehouse of Horror XXXIV
Episodes with stories/dreams
- Simpsons Bible Stories
- Simpsons Tall Tales
- Tales from the Public Domain
- Margical History Tour
- Simpson Christmas Stories
- The Wettest Stories Ever Told
- Revenge is a Dish Best Served Three Times
- Love, Springfieldian Style
- Four Great Women and a Manicure
- The Fight Before Christmas
- Brick Like Me
- Every Man's Dream
- Flanders' Ladder
- Now Museum, Now You Don't
- I, Carumbus
Episodes that show predicted futures
- Bart Gets an "F"
- Itchy & Scratchy: The Movie
- The Front
- Lisa's Wedding
- Bart to the Future
- Future-Drama
- The Boys of Bummer
- Holidays of Future Passed
- Days Of Future Future
- A totally fun thing that Bart will never do again
- Barthood
- Mr. Lisa's Opus
- Flanders' Ladder
- Daddicus Finch
- The credits of Hail to the Teeth
- Sorry Not Sorry
- Mother and Child Reunion
- When Nelson Met Lisa
- It's a Blunderful Life
Other episodes
- The Simpsons 138th Episode Spectacular
- The Simpsons Spin-Off Showcase
- The Principal and the Pauper
- Missionary: Impossible
- Behind the Laughter
- Gump Roast
- Moe Goes from Rags to Riches
- The Man Who Came to Be Dinner
- Every Man's Dream
- The Serfsons
- My Way or the Highway to Heaven
- Thanksgiving of Horror
- Uncut Femmes
- A Serious Flanders: Part One
- A Serious Flanders: Part Two
- Poorhouse Rock
- Lisa the Boy Scout
- Not It
- Homer's Adventures Through the Windshield Glass
Games
All video games featuring Treehouse of Horror or other non-canon characters are considered non-canon.
- Bart vs. The Space Mutants
- The Simpsons Arcade Games
- The Simpsons: Bart vs. the World
- Bart's House of Weirdness
- The Simpsons: Bart vs. The Juggernauts
- Krusty's Fun House
- Bartman Meets Radioactive Man
- Bart's Nightmare
- Bart Simpson's Escape from Camp Deadly
- The Simpsons: Bart & the Beanstalk
- Virtual Bart
- The Itchy & Scratchy Game
- Itchy & Scratchy in Miniature Golf Madness
- The Simpsons Cartoon Studio
- The Simpsons: Virtual Springfield
- The Simpsons Bowling
- The Simpsons Wrestling
- The Simpsons: Night of the Living Treehouse of Horror
- The Simpsons Road Rage
- The Simpsons Skateboarding
- The Simpsons: Hit and Run
- The Simpsons Game
- The Simpsons: Minutes to Meltdown
- The Simpsons: Tapped Out
- LEGO Dimensions