Breaking the Fourth Wall for humorous purposes (being defined as a character breaking the fourth wall in a series whose fourth wall seemed relatively hard) is often the work of a single character who shows Medium Awareness for the joke's sake.
Because the medium-aware character is thereby breaking the established rules of the setting, it is frequent for other characters not to share their fellow's insight, and involuntarily add weight to the joke by asking, "Audience? What Audience?" However, perhaps funnier still is another character knowing perfectly what the wall-breaker is talking about, but immediately shushing him because the characters aren't supposed to know as far as the viewer is concerned. A variation will have the characters complain to the author for writing a fourth-wall-breaking in the first place.
A humorous, fourth-wall version of The Masquerade. A possible interpretation of such a scenario is that there is really No Fourth Wall but the characters pretend there is one anyway. Almost always Played for Laughs.
- Happens several times in the Harry Potter fanfiction The Many Harry Potters of Little Hangleton. And the scolders are right, too, because by the time the fic ends, the Fourth Wall literally shatters on screen, and the next chapter, having literally No Fourth Wall, ends up veering into Gainax Ending.
- Pokémon fanfiction "Child of Mew" has Ash and Mew sometimes breaking the fourth wall. One instance has Ash calling Mew out by saying, "What did we say about breaking the fourth wall?"
- When Mystery Science Theater 3000 featured Manhunt In Space, Tom looked at a planet and quipped "Look, it's the MST3K logo." Joel promptly whispers "You're not supposed to know that!"
- In the Gamera episode, when they see Gamera lured into a rocket ship, Crow says "Hey Joel, remind you of anything?" followed by Servo singing the theme song "In the not too distant future...". Joel responds by pulling Crow's arm off and hitting Servo on the head with it. "I'm gonna sue you for using that song!"
- Monty Python's Flying Circus: At the end of the "Crunchy Frog" sketch, Inspector Praline arrests Mr. Milton:
Milton: It's a fair cop.
Praline: Stop talking to the camera.
Milton: I'm sorry.
- Checkerboard Nightmare broke the fourth wall constantly, but wasn't above mocking the concept as well. In one story arc, Vaporware decides that fourth-wall-breaking is just a crutch for lazy comedy writers, and he completely bricks over the fourth wall so it can never be broken again. (Naturally, a Snap Back undoes this at the end of the arc.)
- The Inexplicable Adventures of Bob!'s title character is prone to fourth-wall-breaking, and his down-to-earth girlfriend Jean always calls him out on it.
Molly: Hey, mommy! Daddy's breaking the fourth wall! It's all avant-garde and stuff! Keen, uh?
Jean Poule: Oh, I hate it when he does that. It's so confusing.
- The Order of the Stick: At one point Elan (accidentally) breaks the fourth wall by noticing how characters looked different before a character design update, only for another character to explain (between their teeth) that they were supposed to have always looked like the modern design.
- An exchange from Paradox Space begins when Karkat uses Dave's terrible webcomic characters in his screenplay. Dave threatens to sue before Karkat says that his "Geromy" is completely distinct from Dave's "Jeromy". Dave points out that it's only a difference of spelling and Karkat screams at him for getting meta. Dave points out he knew the spelling from the script and that Karkat is the one being meta. From there, the argument devolves into cursing.
- In the SuperMarioLogan episode "Bowser Junior's Clown Car", Junior enlists Joseph and Cody's help to get a box that has Bowser's Clown Car in it, since he's too short. Cody points out that he, Junior, and Joseph are controlled by hands, and can go as high as they need to go, leading to this exchange:
Junior: Stop breaking the fourth wall, Cody!
Joseph: Yeah, Cody! Always ruining stuff!
- Yu-Gi-Oh! The Abridged Series is no stranger to breaking the fourth wall, but it eventually got to the point where breaking the fourth wall itself was an in-universe plot. One episode has Shadi revealing to Yugi that it's his job to prevent the fourth wall from being broken and if it was, then chaos would ensue.
- Phineas and Ferb has Major Monogram chewing out Carl for one such instance.
Major Monogram: Carl, what did I tell you about breaking the fourth wall?
- Steven Universe: During a trip to Korea in "Steven's Dream", Greg and Steven walk into their own show's animation studio, in the middle of animating the current episode. Steven is genuinely confused, while Greg gets really nervous once he sees the model sheets, immediately ushering Steven and himself out.
- The Teen Titans Go! episode "The Fourth Wall" uses this as a running gag, where the Titans interact with the audience, much to the chagrin of Control Freak.
- Parodied in Family Guy when Chris tries warning Meg that she's breaking the fourth wall, despite the fact that they're already being filmed for a reality show.