Code Lyoko is a French animated television series featuring both conventional animation and CGI animation. It was produced by Antefilms during the first season and is currently being produced by MoonScoop, both in association with the France 3 television network and Canal J. It first aired on September 3, 2003, in France on the France 3 network. It was first aired in the United States as part of Cartoon Network's Miguzi block on April 19, 2004. Season 4 finished in France on November 10, 2007, while it is still ongoing on Cartoon Network, although the show is not currently being aired.

Code Lyoko is about a group of five boarding school students, enrolled at Kadic Junior High School, named Aelita, Jeremie, Odd, Ulrich, and Yumi. The students travel to the virtual world of Lyoko — which is found in a supercomputer housed in the basement of an abandoned factory near Kadic Junior High School (which they attend) — to fight against a megalomaniacal digital entity named Xana.

The series ran for four seasons, the final of which has yet to finish airing in the US, and three animated films are planned for release.

"Code Lyoko" tells the story of a group of students who uncover a parallel universe called Lyoko inside a super-computer that is threatened by a renegade program named XANA that could destroy the world. It's up to four boarding school students named Jeremy, Yumi, Ulrich, and Odd to help a humanoid being inside Lyoko named Aelita to stop the rogue program X.A.N.A and his plans to attack their world. Jeremy, who is in love with Aelita, struggles through season 1 to find a way to "materialize" aelita, so she can become human by exiting the scanners that connect Odd, Ulrich, and Yumi to Lyoko. If Jeremy accomplishes this, he will be able to shut down Lyoko and defeat XANA. In the episode "Code: EARTH", we witness Jeremy finally materializes Aelita, and accomplishes his dream. The group deactivate Lyoko, but the didn't guess what would happened. XANA apparently infected Aelita with a virus before she was materialized so that if XANA goes, she does too! After being distraught by this dilemma, Aelita and Jeremy spend time together. After returning Aelita to her temporary home, Yumi's house, Jeremy heads back home. In the beginning of season 2, we witness the dawn of new technology. Jeremy programs vehicles into Lyoko, for faster travel, and he also makes a better scan program to detect "activated towers", so Aelita can live on earth, without having to stay in Lyoko to look out for XANA's attacks on earth! ALong with that, Jeremy announces that he is working on an anti-virus good enough to save Aelita from XANA! Franz Hopper, a brilliant scientist, seems related to Aelita after some research. After discovering the Lyoko gang discovers the truth, we learn that Aelita was created on Lyoko as the guardian of it by Franz Hopper. Lyoko and even XANA were made by him, although XANA became evil by himself. With Jeremy, Odd, Ulrich, Yumi, and Aelita against XANA, we're sure to experience a great adventure! Written by Christapheo