This articles lists and describes characters from the BBC and Alliance Atlantis-produced children's television series Ace Lightning, which involved characters from a video game materialising in a small American town. The series was told from the point of view of Mark Hollander, a British teenager who is enlisted as the sidekick of superhero of Ace Lightning and do battle against Lord Fear and his minions. The series combined live actors with computer animated characters.
The series' protagonists were its principle teenage cast, and a group of superheroes known as the Lightning Knights, who come from the game world the Sixth Dimension. The main character is Mark Hollander, who shares the role of protagonist with Ace Lightning.
The heroes of the video game, the Lightning Knights are a group of superheroes who guard the Sixth Dimension from evil. The Lightning Knights operate from the Thunder Tower, an unoccupied observatory in Conestoga Hills. They need to constantly recharge their energy using a transformer or will fade away back to the Sixth Dimension. The Lightning Knights search for the Amulet of Zoar's fragments, a triangular-shaped magic artefact which can open portals and summon characters from the game.
The villains of Ace Lightning, referred to as the "Evil Gang" in some materials all originate from the Sixth Dimension, save Kilobyte. Led by Lord Fear, the villains operate in the Carnival of Doom, an eerie amusement park. Their goal is to conquer the world using the Amulet of Zoar, though Lord Fear would prefer to destroy the human world. Unlike the Lightning Knights, the villains are blasted into an item located around the carnival that symbolise them, until they recover and emerge again. In the show, they take over the rundown Kent Bros. Carnival.