List of fourth wall breaks

The term "breaking the fouth wall" mainly means that the character acknowledges that they are in a cartoon.

Patrick holding a time card.

In rare instances, characters would even reference past episodes or other different cartoon series. So far, the episode to hold the record for most fourth wall breaks in that single episode is Krusty Krab Training Video.

Episodes

Season 2

• In Your Shoe's Untied, though it was part of the song, SpongeBob was seen pulling on the shoe laces on the "Loop de Loop" card.
• In No Free Rides, SpongeBob actually ran over the Narrator in the beginning of the episode.
• In Imitation Krabs, Mr. Krabs tells directly to the viewers that he is not a robot.

Season 3

• In Club SpongeBob, Squidward said "Why must every eleven minutes of my life be filled with misery?!" Eleven minutes happens to be the length of the episode.
• In Missing Identity, When Patrick stopped laughing, he says "Sorry people", probably referring to the audience. Also the cafe lady says "You've managed to kill eleven minutes." referring to the length of the episode.
• In Wet Painters, Patrick was actually holding one of the time cards and even said "Could you move it along? I'm all out of time cards."
• In Born Again Krabs, Mr. Krabs looks at the viewers while telling the kid that he is no longer cheap by saying I was, son. I was
• In Krusty Krab Training Video, the Narrator talks directly to SpongeBob and the viewer for most of the entire episode. Squidward and Patrick also seem to notice the Narrator talking as well.

Season 4

• In All That Glitters, as SpongeBob was rolling on the ground crying, another image of SpongeBob appears on the screen saying "All that glitters, is not gold." This actually breaks the fourth wall in two ways as SpongeBob was talking to the viewer and referenced the episode title.
• In Krabs vs. Plankton, SpongeBob hums the theme song of the series.
• In Born to Be Wild, SpongeBob actually rode the bubble transition to quickly get into the Krusty Krab and warn Mr. Krabs. Mr. Krabs was shocked wondering where SpongeBob came from.

Season 5

• In New Digs, SpongeBob appeared to be singing along to the title theme for this episode.
• In Pat No Pay, SpongeBob says, "He needs one, or he'll keep mumbling about it for the next three and a half minutes." 

Season 6

• In Shell Shocked, SpongeBob suddenly appeared in Angry Jack's commercial.

Season 7

• In SpongeBob's Last Stand, when Mr. Krabs wanted to know when the approval of the Shelly Superhighway was passed, Plankton responded "Observe in this conveniently timed flashback."

Season 8

• In Drive Thru, after one of Pearl's friends screamed in Squidward's ear with a megaphone, Squidward held his ear in pain and talked directly to the viewers saying "I'm not faking it y'know. It really hurts...a lot..."
• In Planet of the Jellyfish, the time card "Eleven Minutes Later" was shown which was the length for that episode.

Season 9

• In Plankton's Pet, Plankton shouted out "Holy plot twist!" when Spot brought him a Krabby Patty.