Sissi's Gang is the small, yet influencal group that Sissi founded. It constantly fights with Team Lyoko, and considers itself popular. It has a lot of affect on Mr. Delmas's decisions, as he is Sissi's father.
- Sissi Delmas - Leader of the group; the spoiled, conceited daughter of the principal of Kadic.
- Herb Pichon - Second-in-command. Brains of the gang.
- Nicholas Poliakoff - Dumb muscle, and foil to their plans.