Jeremy Belpois (in french Jérémie Belpois, pronounced as "Jerr-mee Bell-Pwah") 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.
Since the episode "Franz Hopper", he's 13 years old. Jeremie is a big student admired by his professors, and he's the brain of the group of Lyoko-Warriors (even many times is called "Einstein", especially by Odd) and a big expert in computers. His father, Michael Belpois, tries to convince it to go to a school of gifteds, but is very understanding with the decisions of his son as it shows in "Distant Memory". He's in love of Aelita, he loves her company and always goes with her more than with the rest. Jeremie operates at the factory helping his friends in their missions. In all the first season he worked in the materialization of Aelita. Later, he develops diverse items to help, like the vehicles, and looks for the antivirus perfect for Aelita. Although it has not showed to the public his appearance, Jeremie was virtualized in Lyoko thrice (one in the season 5 of fans) and has scanned four times, for the moment.
In "Alone in Lyoko" is virtualized by X.A.N.A. for the first time in Xanadu, the new Replika in the season 5, but his appearance is seemed as in Earth.
In this alternate continuity, Jeremie still acts as the group operator.
Here, Jeremie is a tad quirkier, going off on tangents about his work and openly expressing his passion for technology like a mad scientist. It is also implied that he does not take too kindly to having his equipment messed with, as Ulrich feared what might happen if he damaged Jeremie's robot parts. He's also not above putting bets about Ulrich and Yumi's relationship, albeit he only bet five euros, and was called a cheapskate by Milly and Tamiya. As he does not possess an infatuation with Aelita in this continuity (Owing to her lack of presence), he is more straight forward when dealing with the virtual world of Xanadu.
As Jeremie is still the group operator, he has not displayed any combat skills, and likely still has none. His skills remain more on the technical side of things, being capable of building working robots and understanding the calculations regarding Xanadu's effects on the real world, as well as operating the supercomputer in general.