John Barth does this all the time. In “Dunyazadiad,” the first book of Chimera, Barth shows up in Shaharazade’s bedroom. In “Bellerophoniad,” there’s a discussion of how the story resembles Joseph Campbell’s archetype.
“Lost in the Funhouse” is a story where Ambrose is lost in a funhouse and tries to get out by imagining he’s the character in a story about being lost in a funhouse. The character also gives advice on how to write a story.
LETTERS has Barth as one of the characters.
Gene Wolfe’s Book of the New Sun ends each volume with a paragraph saying something like, “Reader, I’ve taken you this far. You may not want to continue.”
Two novels that don’t explicitly break the third wall, but seem to be speaking directly to the reader rather than to a journal or someone else in the room are The Martian by Andy Weir and The Life of Pi by Yann Martel. In many ways this is similar to RealityChuck’s suggestion of Moby Dick, etc. Many narrative books written in the first person with more details than would ever be written down or said aloud break the fourth wall simply due to the style.
It’s may not what the OP means, but I always felt like Stephen King’s Dark Tower books regularly broke the fourth wall by referencing other books or characters in his novels. If you hadn’t read those novels, the references might be totally lost on you, though the idea of interconnecting all of his works was an intentional point of the Dark Tower series. I seem to remember that Stephen King himself appears in the novels.
Don Quijote does this vividly. Besides the story-within-a-story tricks, at the start of the second part, Cervantes addresses the reader by (IIRC) having Quijote talk about how Cervantes is telling you the REAL story. IRL, this was in response to someone who pretended to be Cervantes and published an unauthorized Quijote sequel.
In The Number of the Beast, Heinlein has one of his point-of-view characters say, “Let me tell you, you nonexistent reader sitting there with a tolerant sneer. Jane is more real than you are.”
Clearly breaking the fourth wall, certainly. But it also foreshadows…
…the later discovery in the book that all universes are merely fiction in another universe. So the character is speaking nothing but literal truth. There’s a reader out there who he fears is mocking him.
I’m pretty sure that most books written in the first person never “break the fourth wall”, the narrator just says “I did this and I did that” without ever addressing the reader. There are also stories where a first person narrator may be telling their story to a “you” who is clearly another fictional character, as in an epistolary novel.
There are plenty of exceptions though, as this thread shows. One that hasn’t been mentioned yet is A Clockwork Orange. Alex addresses the reader as “you” and “my brothers” in a rather old-fashioned way. There’s also The Princess Bride, where William Goldman addresses the reader as part of the framing device where he’s editing/abridging the “original” S. Morgenstern novel.
Actually, both The Hobbit and Lord of the Rings directly talk to the reader in a few places - although in LOTR that gets quickly dropped in the shift in style from ‘telling a kid’s story’ in the first half of Fellowship to ‘Noble Historic Saga’ for the rest.
Well, I have to disagree with “someone” then. First person narratives are often presented as the narrator’s thoughts and not a story being told to or written for anyone else. In theater characters sometimes share their thoughts with the audience through a soliloquy, but this isn’t considered a breaking of the fourth wall. It’s only breaking the fourth wall if the character directly acknowledges the audience.
In what is possibly the best locked room mystery of all time, John Dickson Carr’s** The Three Coffins**, detective Dr. Fell comes right out and says that the story is just detective fiction and his lecture on how locked room puzzles as a whole may be solved is purely for those interested in an academic discussion of the genre.
Specifically, the character of Don Callahan (who first appears in Wolves of the Calla, and also appears in Song of Susannah and The Dark Tower - books 5-7 of the Dark Tower series) finds out that he is a character in 'Salem’s Lot, yet is real in the Dark Tower series. And Roland and Eddie have to come to “Keystone Earth” to get King to keep writing the Dark Tower books.
