The Lyoko Warriors (also referred to as "Team Lyoko", "the group", or "the gang") is the name given to the group of main characters in Code Lyoko; Ulrich Stern, Yumi Ishiyama, Aelita Schaeffer, Jeremie Belpois, Odd Della Robbia, William Dunbar, and later, Laura Gauthier. The Lyoko Warriors battle the evil, multi-agent computer program named X.A.N.A. so that he does not gain control of Earth and beyond. They also try to gain more knowledge about Aelita, Franz Hopper, and X.A.N.A.. The Lyoko Warriors are constantly at odds with Sissi's group.
In the first season, the sole purpose of the Lyoko Warriors was to materialize Aelita and shut down the Supercomputer so that X.A.N.A. would not interefere with the outside world. They achieved this Code: Earth, however. X.A.N.A. planted a virus in Aelita which killed her if the Supercomputer were to shut down.
In the second season, following the revelation that Aelita had a virus inside of her, the group continued fighting in search of a "cure" for Aelita. However, with the introduction of Franz Hopper and Sector 5, the group's goals were increased. It was gradually revealed that Hopper was Aelita's father, and that he built Lyoko as a sanctuary for Aelita and him, and X.A.N.A. was originally a program to destroy Project Carthage, a military program that involved his advances in time travel. X.A.N.A. eventually escapes during an attempt to cure Aelita by completely wiping out her memory and thus killing her. Hopper however appears and revives her and restores her memory. X.A.N.A., now free from Lyoko's boundaries, is now located on the web.
The third season features Jeremie trying to figure out how to access Sector 5. X.A.N.A. is still sending attacks, however these attacks are more powerful and strong as he is now in the web. Throughout the season, X.A.N.A. attempts to wipe out the four sectors to prevent the team from accessing Sector 5. He eventually does through a possesed Aelita, by wiping out the sectors one-by-one. William joins the team so team has better changes to fight X.A.N.A. He however gets captured and possessed.
In the fourth season, the group has a whole lot on their list: rebuilding Lyoko, recovering William, traveling the web in search for X.A.N.A., trying to cover up William's disappearence, finding Franz Hopper, along with the everyday issues of school and life. Through the course of the season, these goals are fulfilled however with the cost of Franz Hopper's life and a handful of questions left unanswered.
In the fifth season, they're trying to piece together X.A.N.A.'s return, and how Franz Hopper is connected to it. They discover a replica called the Cortex which contains valuable information. Odd, Ulrich and Yumi have ability to use the towers same way as Aelita, but all four of them are targeted by X.A.N.A. who needs their source codes, which he can only steal through spectres in the real world. William proves himself to the team and is accepted back. Also Laura joins the team as an aid for Jeremy at the lab. With William and Laura into the group, the team will try to investigate who revived X.A.N.A. and why. Unfortunately, they encounter new enemies called "The Ninjas".
The current members consists of seven junior High School children.
- Ulrich Stern – Ulrich is hot-headed, stubborn, and shy, although loyal and thoughtful. In the first season, Ulrich was the apparent leader in Lyoko, however his role as this was diminshed in the following seasons. Ulrich is a samurai on Lyoko, with the abilities to split into three ("triplicate") and run very quickly ("super sprint"). His weapon is a sword, although in the fourth season, he was given katanas (dual swords). Ulrich is Yumi's love interest and their relationship is, to say the least, "complicated". Back then, he and William were big rivals, trying there best to catch Yumi's attention. Later on in Rivalry, Ulrich got assistance from his rival, thus allowing William to officially rejoin the group. As of now, they are now friends.
- Yumi Ishiyama – Yumi is the mature one of the group, that is, the person who offers common sense and ideas when the others are too incompetent or scared. Yumi is the oldest and is somewhat the leader, however this role is not "officially" established. Yumi is a geisha on Lyoko, reflecting her Japanese heritage and has the ability to move things with her mind ("telekinesis"). She is also gifted in aerobatics as she can balance herself in sticky situations. She is Ulrich's love interest, however throughout the show, she states that she is not interested but this proves not to be the case.
- Odd Della Robbia – Odd is of jokester of the team, and he constantly makes jokes constantly, much to his team members' annoyance. Odd has blonde hair with a purple streak. Odd is messy, disorganized, and cheap although he is loyal and honest. Odd acts more of a member than a leader, although he has taken command on occasion, especially in Marabounta. Odd is a cat on Lyoko and defends himself with laser arrows and his shield. Odd originally had the ability to see the future, however this was ability was later removed.
- Jeremie Belpois – Jeremie is more often than not the team's main leader strategist, as well as their source of intelligence. Jeremie acts as "the operator"; he manages everything for virtualizing and devirtualizing, anything that does with the Supercomputer. He is Aelita's love interest and their relationship has been featured on the series, although not as heavily and Ulrich's and Yumi's.
- Aelita Schaeffer – Aelita was originally thought to be just a program until she was materialized and her history was revealed. She has the ability to use the interfaces in Lyoko. Originally a defenseless elf on Lyoko, Aelita becomes a strong angel (with wings) in the fourth season. Her main weapon is energy fields which can destroy monsters on contact (excluding Megatanks) and she also possesses the ability to alter, control and manipulate the landscapes and terrain of Lyoko or create invulnerable clones of herself (Creativity), she is also able to freeze her enemies in a block of ice (Petrification). She has a new rival (similar to Ulrich and William's rivalry) named Laura Gauthier, who both compete for Jeremie's heart (again, similar to Ulrich and William competing for Yumi's heart). They were both hostile to each other, until in Rendez-vous where Aelita thanks Laura for helping Jeremie.
- William Dunbar – The sixth warrior. At first, William was immature when it came to fight X.A.N.A., much to the annoyance of his team members. On his first battle on Lyoko, he was possessed by X.A.N.A. and destroyed the Core. For the most part in the fourth season, William was possessed and battled the group in addition to X.A.N.A.'s monsters, until being rescued in Down to Earth. William's avatar was a Doppelsöldner when he first went to lyoko. Before then, the Lyoko Warriors were wary of him going to Lyoko and back to joining the group but in Rivalry, William is fully accepted back in to the group when he helps out Ulrich on a mission in Lyoko. William is the only other member of the group that is the same age as Yumi. He is also the oldest member of the group.
- Laura Gauthier – The seventh and newest warrior. Laura made her first appearance in Code Lyoko Evolution where she corrected Jeremie on a question. She helped out the team on a mission in Lyoko. Laura wanted to join the group, but instead, was denied by Aelita. Like William, Laura started to remember bits and pieces of her memory in which she helps the group. In Virus, she is accepted into the team, not only because she helped out, but because she altered the program into the Core of Lyoko, allowing her to be invulnerable to the return to the past. Laura is mainly considered as Aelita's romantic rival, as she seems to deeply be romantically attracted to Jeremie.
Temporary members and aidesEdit
- Jim Morales – Member in Code: Earth and False Start. Having been fired by the principal for breaking Jeremie's ankle during a heated chase, he decided to prove himself by assisting in the battle against materialized Roachsters and was supportive and kind to Aelita, even checking her pulse and speaking very respectfully to her. His memory was erased by time reversion, though Jim has proven himself many times after this. Jeremie even said at the end of the episode Opening Act that he was tired of explaining the concept of Lyoko to Jim, as a time reversion was about to take place.
- Herb Pichon – Brief member in The Robots. He helped take down a robot X.A.N.A.. created. His memory erased by time reversion.
- Sissi Delmas – Member in Ultimatum, when she operated the Supercomputer. Memory erased by time reversion. She was going to be virtualized in X.A.N.A. Awakens, but was later deemed a traitor by Ulrich when she breaks her promise not to tell anyone about Lyoko. Sissi joins the group in the finale of fourth season. She is the only temporary member who wanted to go to Lyoko but never had a chance.
- Chris Morales – Brief member in Opening Act by helping the group hold off a polymorphic clone during a battle. Memory erased by a return in time.
- X.A.N.A. – A temporary truce between Team Lyoko and X.A.N.A. occured in Marabounta as Aelita was being targeted due to X.A.N.A.'s virus. X.A.N.A. needed her memory and thus helped destroy the Marabounta. This truce however only lasted for one episode and a similar event didn't reappear until Common Interest, where X.A.N.A. helped Jeremie save Aelita and X.A.N.A. in the process by replacing the supercomputer's powersource.
- Patrick Belpois – Appeared in one episode and is also Jeremie's cousin. He helped stall the X.A.N.A.- possessed Sissi and Herb. His memory was erased since Jeremie asked Aelita to activate a time reversion to heal his injuries from the attack of a possessed Sissi.
- Kiwi – The only non-human member of the group. Kiwi was brought to Kadic as Odd's pet, much to the dismay of Ulrich. Kiwi has displayed a low degree of intelligence, and has proven useful to the group on occasion. Kiwi was supposed to be the first one to go into Lyoko, but Odd became the test subject instead with his attempt to save his dog in X.A.N.A. Awakens. Kiwi also helped Odd reload his arrows once, although accidentally. He does not appear in Code Lyoko Evolution.
- Hiroki Ishiyama and Johnny - Aided Yumi in hacking the military satellite in Hot Shower, memories erased via time reversal.
- Jeremie, Laura, and Aelita are the smartest ones in the team. Yumi and William are also a bit smarter, while Ulrich isn't very good at it. Odd usually doesn't bother to try (such as in Final Mix where he made a paper crane instead of finishing his test).
- Laura is the only Lyoko Warrior who has not been virtualized. However, In the episode Friday the 13th, she almost went to Lyoko to assist Odd, but was stopped by Aelita.
- Ulrich, Yumi and Laura are only ones who haven't been possessed (or in Odds case zombified) by X.A.N.A.. Not counting X.A.N.A. taking control over Ulrichs body once.
- All of the Warriors have used "Lyoko Warriors" as the team name at one point or another. It is mostly used as the team name in Evolution. It can be assumed that Odd came up with the name.
- At some point, every Lyoko Warrior apart from Aelita and Jeremy have been kicked out of the group.
- Laura is only member whos not been target of X.A.N.A attacks.