[[quoteright:350:[[VideoGame/BanjoTooie http://static.tvtropes.org/pmwiki/pub/images/Tooty.jpg]]]]
[[caption-width-right:350:[[Creator/{{Rare}} They]] were [[LampshadeHanging well aware of this trope]] and [[{{Pun}} milked it]] for all it's worth.]]

->''"Let us contemplate the mystery of Richie's older brother Chuck, who ascended the stairs with his basketball in season one, and never came down again."''
-->-- '''Peter Griffin,''' ''WesternAnimation/FamilyGuy,'' "The Father, the Son, and the Holy Fonz"

Generally, if writers want to remove a character from their ensemble, they will either [[CharacterDeath kill that]] [[DroppedaBridgeOnHim character off]] or [[PutOnABus put him on a bus]] ([[TakeAThirdOption or]] [[BusCrash both]]) to explain their absence. Sufferers of Chuck Cunningham Syndrome, on the other hand, simply disappear into limbo. They will often be {{retcon}}ned right out of the story's history, and everyone still left on-screen will simply carry on as if the character never existed or had any impact on the story. This is sometimes caused by the writers gradually losing interest in the character and, without making a conscious decision to remove them, eventually forgeting about them entirely. More often, complications behind the scenes drive the decision to remove a character.

The [[TropeNamers Trope Namer]] is Chuck, who was actually Richie Cunningham's older brother for two seasons on ''Series/HappyDays''. Remember him? No?

[[AppealToObscurity Exactly]].

In recent years, though, as media has become more meta, playful references to the ignominiously departed have become common, either as [[LampshadeHanging lampshades]] within the series itself or in parodies or satires of it.

A subtrope of UnPerson, although this trope isn't necessarily intentional. Similar in spirit to TheOtherDarrin, wherein a character's actor or voice is replaced and nobody in-universe seems to notice or care. Also see OutOfFocus, when a character is gone but not ''quite'' forgotten; SequelNonEntity which is a subtrope that's concerned with a character not returning for a sequel in particular rather than vanishing from the series as a whole, and ShooOutTheNewGuy, who gets at least an excuse in the show for disappearing. Contrast with RememberTheNewGuy, where someone comes in out of nowhere sometime midway through and the series acts as though they've been there the whole time. For characters who are written out of the main story but are still hanging around in view, see DemotedToExtra. For characters who are specifically brought in for a one-shot purpose, see LongLostUncleAesop. For characters that are given a reason for their departure ''and'' an on-screen send-off, see PutOnABus. Compare ForgottenFallenFriend. If a character appears in the pilot or very early episode of a show and [[DroppedAfterThePilot then vanishes]] it may be a case of EarlyInstallmentWeirdness. See also AbsenteeActor. PresentAbsence is when this is averted and a character's absence is not only noticed in-story, but is often a major driver of the plot. WhatHappenedToTheMouse is this for minor aspects like side characters or subplots.

This trope is only applicable to genuine members of the ensemble who would otherwise seem to be a little more permanent, not characters who appear out of nowhere for one or two episodes and vanish just as swiftly.

When this trope happens in-universe, with the character having his existence literally erased, it's a {{Retgone}}.

%% '''Note:''' when adding examples, this trope is specifically about characters who disappear ''entirely'' without explanation. If they reappear even briefly, or if their absence is explained in-show even flimsily, it is more likely one of the alternate tropes listed.

* ChuckCunninghamSyndrome/{{Advertising}}
* ChuckCunninghamSyndrome/AnimeAndManga
* ChuckCunninghamSyndrome/ComicBooks
* ChuckCunninghamSyndrome/FanWorks
* ChuckCunninghamSyndrome/{{Film}}
* ChuckCunninghamSyndrome/{{Literature}}
* ChuckCunninghamSyndrome/LiveActionTV
* ChuckCunninghamSyndrome/{{Music}}
* ChuckCunninghamSyndrome/NewspaperComics
* ChuckCunninghamSyndrome/ProfessionalWrestling
* ChuckCunninghamSyndrome/{{Radio}}
* ChuckCunninghamSyndrome/TabletopGames
* ChuckCunninghamSyndrome/{{Theatre}}
* ChuckCunninghamSyndrome/VideoGames
* ChuckCunninghamSyndrome/{{Webcomics}}
* ChuckCunninghamSyndrome/WebOriginal
* ChuckCunninghamSyndrome/WesternAnimation
* ChuckCunninghamSyndrome/{{Other}}