A narrator with a French accent introduces SpongeBob SquarePants, a sponge who lives in a pineapple in the city of Bikini Bottom. SpongeBob’s foghorn alarm clock rings, waking him up in the morning. He tells his pet, Gary the Snail, that he must be in good shape because this particular day is very important. He jumps off of his diving board and lands in his pants. He goes to his exercise room and lifts a bar-weight (which is actually two stuffed animals). Afterwards, SpongeBob exclaims that he is ready.
The film follows the plot of the TV series SpongeBob SquarePants, focusing on the anthropomorphic sea sponge SpongeBob SquarePants (Tom Kenny). It begins with a live action sequence of a pirate crew eagerly awaiting their treasure: tickets to The SpongeBob SquarePants Movie. When they recover it, they sail to the movie theater and sit down at the front row seats to watch the film. In the movie proper, SpongeBob has a dream of becoming the manager of the Krusty Krab restaurant and that the restaurant is in danger because a customer named Phil has no cheese on his Krabby Patty, but SpongeBob comes to save the day. SpongeBob wakes up, and happily gets ready for the Krusty Krab 2 opening ceremony, with the hope that his boss Mr. Krabs (Clancy Brown) will promote him as manager of the new restaurant. At the opening ceremony, SpongeBob is denied the title, which is instead given to his co-worker Squidward Tentacles (Rodger Bumpass), due to being "more mature" than SpongeBob and Mr. Krabs thinking that he is "just a kid" and unable to handle the task.