Jeremie Belpois (also spelled Jeremy Belpois) is one of the main protagonists of Code Lyoko, and a Lyoko Warrior. Jeremie is 12 years old at the start of the series, but with the intellectual and scientific, gifted and talented mind of someone far beyond his years. He acts as the guide in Lyoko, since he is able to run the computer that no one else can (besides Aelita). It is also Jeremie's discovery of the Supercomputer that commences the group's quest to materialize Aelita into the real world, which is revealed in X.A.N.A. Awakens. He's noble, but sometimes has a short temper. He is also the most vulnerable to being possessed by X.A.N.A., the reason for his susceptibility is unknown, but it is believed that his lack of experience in fighting X.A.N.A's monsters on Lyoko may contribute to this.
Jeremie, being the stereotypical nerd, in what he has in book smarts, he lacks in common knowledge. He sometimes tends to forget that there are others that are not as smart as him, making comments on the simplicity of the supercomputer to the other Warrior who couldn't possibly understand it with out detailed guidance (with the exception of Aelita and Laura). He can also be seen as a hot-head at times, as well as a workaholic, with defeating X.A.N.A. constantly on his mind, causing him to sometimes snap on the other warriors. He also appears to be very mature, despite being the youngest.
- He will make his first appearance in Code Lyoko: The Lost Laboratory.