Continuity mistake: When Patchy lifts his eye patch to rub his eye and puts the patch on his right eye. In the next shot the patch is on his left eye.
Naughty Nautical Neighbors / Boating School - S1-E4
Continuity mistake: When Squidward starts making pink bubbles with messages, he goes to his backyard. Notice he never closed the back window of his house. When he starts laughing because of the messages, suddenly the window is closed. After Patrick saves Squidward, the window is still closed, but when they go to the front of his house, the window is open.
Mermaid Man and Barnacle Boy III / Squirrel Jokes - S2-E4
Continuity mistake: During Spongebob's act, he says to the audience, ".I'd like to give a special thanks to my friend Sandy over here" and the spotlight moves from Spongebob to Sandy. A few shots later, when Spongebob is talking to Sandy, the spotlight is suddenly no longer on Sandy. Then when Spongebob yells "Am I right?" to the audience, the spotlight is on him and as he turns to talk to Sandy again, the spotlight is altogether gone; it's not on either one of them.
Krab Borg / Rock-a-Bye Bivalve - S3-E8
Continuity mistake: In the scene where SpongeBob has given his pants to the clam, two continuity errors appear. First, Patrick puts his head in the pants and he says that the clam is hungry. A lot of holes are in his head. In the very next shot, the holes are gone. This is really obvious. The other continuity error is that before Patrick gets those holes, SpongeBob isn't with his pants. When he tries to give the Patty to the clam, he's suddenly with his pants, when the little clam is supposed to have his pants.
No Free Rides / I'm Your Biggest Fanatic - S2-E10
Continuity mistake: In "No Free Rides", when Spongebob and Mrs. Puff are fighting in the car, they eventually go over a cliff. We see a view of a police car under them, next to the cliff and a billboard. We also see a shot of the police car facing a hill or two. The car flies out of nowhere onto the police car, from behind a hill, not off the cliff. The landscape in the scene changes in each shot.
Pressure / The Smoking Peanut - S2-E12
Continuity mistake: In The Smoking Peanut, after Spongebob sees Sandy he runs home. When he's trying to open the door if you look to the right the ground is completely flat and has nothing in it. Yet when Patrick comes, while he is saying, "I followed these footprints to this exact spot", there are footprints.
The Sponge Who Could Fly (aka The Lost Episode) - S3-E16
Continuity mistake: When the tape pours out of the VCR at the end of the show, Patchy the Pirate gets tangled in it. A shot later, the tape is three times longer than it was the shot before it.
Jellyfishing / Plankton! - S1-E3
Continuity mistake: In "Plankton", when Plankton is controlling Spongebob, Spongebob goes to put his pants on, but Plankton has him walk through them. As they're walking towards the pants, the tie is red. As they're walking through the pants, the tie turns black. As they walk away from the pants, the tie is red again.
No Free Rides / I'm Your Biggest Fanatic - S2-E10
Continuity mistake: When Spongebob writes an essay, at first he's in the middle seat on the front row, but after he gets his pen, he sits down at the desk to the very right.
Suggested correction: No, he is sitting in the middle the whole time.
Something Smells / Bossy Boots - S2-E1
Continuity mistake: When SpongeBob shows Patrick his sundae Patrick's eyebrows burn. In the very next shot, they're back.
No Weenies Allowed / Squilliam Returns - S3-E6
Continuity mistake: In "Squilliam Returns", when Squilliam arrives at the "5-star restaurant" it is nighttime, but at the end when Squidward says "Will you get out of here!" to Mr.Krabs and it zooms out on the Krusty Krab it is daytime.
Audio problem: In the episode "Rock Bottom" when Spongebob says "Another funtastic day at glove world," near the beginning, if you watch Spongebob's mouth, it only says "Another funtastic day at." It never says "glove world."
The Snowball Effect / One Krabs Trash - S3-E3
Continuity mistake: In "The Snowball Effect", sometimes Sqidward's doorknob is on the left, and sometimes it's on the right.
The Snowball Effect / One Krabs Trash - S3-E3
Continuity mistake: In "The Snowball Effect" when Patrick tries to make a snowball the third thing he makes is a DNA strand, if you look closely, when it is in closer, the DNA strand is shorter than when they go out on it.
Revealing mistake: Near the end of "Rock Bottom", when SpongeBob arrives back to Bikini Bottom, SpongeBob's pineapple is animated differently from the other buildings. It looks like it was cheaply tacked on in post production.
Enemy In-Law/Mermaidman and Barnacleboy VI: The Motion Picture - S4-E7
Other mistake: Plankton's phone doesn't have a 0 button on it.
Dying For Pie / Imitation Krabs - S2-E6
Revealing mistake: In the episode "Dying For Pie", you can see Mr. Krabs' legs disappear when Squidward says, "But you can't pay me enough to act brotherly on that guy!"
Mermaid Man and Barnacle Boy IV / Doing Time - S3-E1
Continuity mistake: At the start of MMIV, SpongeBob rips off a person's pocket to get a pen. He totally rips it off, but none of the pocket's material is visible later.
Goo Goo Gas/No Hat for Pat - S7-E9
Continuity mistake: In the episode where Plankton turns Krabs and the rest of the Krusty Krab into babies, baby Krabs is hitting Plankton with the secret formula while they are on the floor of the Krusty Krab. Krabs crawls away and Plankton picks up the bottle and declares how easy it was. The next shot he is suddenly on top of one of the tables instead of the floor.
Sandy's Rocket / Squeaky Boots - S1-E8
Continuity mistake: Sandy's Rocket: When you first see SpongeBob in bed you can see a mysterious glass window on the floor. When Patrick arrives it has vanished, evident in the wide shot.