|First appearance|| X.A.N.A. Awakens (chronologically)|
|Hair color|| Black|
Blonde (in Evolution)
|Voiced by||Jodi Forrest, Christine Flowers (first few episodes)|
|Portrayed by||Clémency Haynes|
|A beautiful flower like me has to be watered often.|
–Sissi in Uncharted Territory
Elisabeth "Sissi" Delmas is an often mean, spoiled and popular student at Kadic. She often pesters Team Lyoko, most of the time to win Ulrich's affections. However, she admits in Holiday in the Fog that she is gaining their attention through her mean actions towards them. By so doing she is almost making enemies out of her would-be friends, instead of gaining any of their respect, much to her chagrin. At the end of the series, in Echoes, she achieves this at last and becomes an official friend of the group. She is also the daughter of Mr. Delmas, the principal of Kadic, the boarding school she attends and lives in. She is a major recurring character.
Not much is known about Sissi's family life, except that her mother is apparently still alive according to interviews with head writer Sophie Decroisette. She is approximately 14 years of age, and is currently in the eighth grade. In the original scripts of False Pretenses, Sissi reveals to Aelita that she and her mother go shopping every second weekend or so, implying that her parents may be divorced.
She often whines and yells at people if she is provoked or taunted.
She is quite mean to the Lyoko Warriors, particularly Yumi (for also loving Ulrich). However, she has been known to act nicer toward them and even assist them on a number of occasions, particularly in seasons 2 and 4. This stemmed from events in "X.A.N.A. Awakens," in which Ulrich stood her up for a date, starting their feud.
As of "Teddygozilla," she had won 3 annual beauty contests.
Sissi had been seeking Ulrich's affections since the two were in pre-school. In X.A.N.A. Awakens, Sissi is yet again trying to do just this. But when Ulrich doesn't show up that night, she storms off to find him, running into Odd, who is following Ulrich, who kidnapped Kiwi. She goes with Odd to the factory and inadvertently stumbles upon the secret of Lyoko, and becomes a part of the gang. The next day, Sissi expresses her interest in going to Lyoko. However, after being targeted in X.A.N.A.'s attack, Sissi reveals the secret to her father and is kicked out of the group for betraying them. A return to the past is launched, and Sissi never remembers any of the events that happened.
During season one, she made up many plans to get Ulrich to herself or try to join the gang. For example, in Log Book she stole Ulrich's diary and read all about Lyoko, then blackmailed him into dating her. In Holiday in the Fog she stayed back at school during the holiday to spy on Jeremie and try to figure out what he was up to. She also proved herself to be very kind and sincere when she wanted to be, and that she's a very good nurse and helpful during some X.A.N.A. attacks, in episodes such as The Trap, End of Take and again Log Book.
In seasons 2-4 she still retained her gentle side, and wasn't as devious towards the Lyoko Warriors, but was still rather rude and obnoxious at times. At the end of the series, in Echoes, once the threat of X.A.N.A. has been eliminated, Sissi stumbles upon Jeremie's video diary in the lab after using a tracking device to find their hideout. She rants and raves to her father about everything, including her being possessed, but he doesn't believe her. After a return to the past, the group accepts Sissi as a friend.
Being at good side of the team, Sissi stopped meddling with their business. In Code Lyoko Evolution Sissi has a much smaller role, making her first main appearance in the ninth episode, and her second appearance in the twenty-first episode. She can still be seen in classes in other episodes though. Odd now has weird habit of running into Sissi accidentally while walking, earning himself repeated lectures from her.
In False Pretenses Sissi invites herself along to a shopping trip with Aelita and Yumi. While Yumi goes to help with an activated tower, Aelita stays at the school and bonds with Sissi a little, even convincing her to dress up in her clothes and a pink wig to trick the spectre on the prowl. After a return to the past, Aelita is very enthusiastic to have Sissi come along with them.
- Sissi is the only female eighth grader that Odd hasn't kissed. However, she once kissing Odd's nose in Straight to Heart after mocking him.
- She states that she hates her real name and would rather be called Sissi than Elisabeth.
- Sissi is the consecutive winner of Kadic's beauty pageant, three years running. This strongly implies that she and the other schoolchildren have been at Kadic for a while now.
- She was the first character in the show to be possessed by X.A.N.A. and the only one ever to be possessed by Franz Hopper.
- She was also the second character to be attacked by X.A.N.A. (Jeremie was the first).
- In Vertigo, she told Ulrich that William is afraid of spiders. How she knew this is unknown, though Ulrich explains it by saying "I have my spies."
- Sissi was the first character to use the nickname "Mrs. Einstein" for Aelita, which probably came from the nickname "Einstein" used for Jeremie, made up by Odd.
- In the French version of Code Lyoko, her voice is provided by Carole Baillien.
- Sissi's pajamas, introduced in the second season, are pink with pale yellow lace on the shoulders and legs. In season 4 she wears a light pink nightgown with darker pink trim.
- She is sometimes seen sleeping in just her underwear rather than her pajamas.
- She made her debut in Code Lyoko Evolution in How to Fool XANA.
- Made an even more minor character in CLE, only making cameos in two episodes so far.
- Sissi's hair in Evolution is blonde instead of black.
- In Fight to the Finish, Odd tells Sissi if she'll look better with blonde hair.
- Sissi was once a temporary member of the gang. She did want to go to Lyoko, but was very frightened about the idea.
She was the first student, not in the group, to take an interest in the group (in X.A.N.A. Awakens. She never had a chance though, mainly thanks to X.A.N.A.
- She was the first character to be kicked out of Team Lyoko. This was mainly thanks to her mistake of telling the principal, her Father, that Ulrich, Yumi, Jeremie, and Odd were in danger at the factory. It is suspected that this was in an effort to "protect" Ulrich, but instead of protecting him, she took sides against him by revealing a secret that should never have been revealed. Laura did the same thing with her father in Chaos at Kadic, but she was not kicked out of the group due to her immunity to Time Reversion.
|Jeremie Belpois | Aelita Schaeffer | Odd Della Robbia | Yumi Ishiyama | Ulrich Stern | William Dunbar|
|Sissi | Jim Morales | Suzanne Hertz | Anthea Schaeffer | Mr. Delmas | Laura Gauthier | Franz Hopper|
|Kiwi | Herb Pichon | Nicholas Poliakoff | Amelia "Milly" Solovieff | Tamiya Diop | Hiroki Ishiyama | Johnny | Takeo and Akiko Ishiyama|
|X.A.N.A. | Monsters|
|Professor Tyron | Ninjas | X.A.N.A. William|
|Jean-Baptiste Pujol | Theo Gauthier | Emily LeDuc | Taelia | Samantha Knight | Samantha Suarez | Heidi Klinger | Mathias Burrel | Magali de Vasseur | Claire Girard | Brynja Heringsdötir | Patrick Belpois|
| X.A.N.A. Aelita | X.A.N.A. Odd | X.A.N.A. Yumi | X.A.N.A. Ulrich | X.A.N.A. Franz Hopper | X.A.N.A. Anthea Schaeffer | Jeremie Clone | Aelita Clone | William Clone|