* Alex Rider: The protagonist, a 14-year-old boy who is recruited by MI6 to become a secret agent. He is intelligent, resourceful, and determined.
* Jack Starbright: A young genius inventor who is responsible for the creation of Stormbreaker, a high-tech computer system designed to control the world's nuclear weapons.
* Mr. Smith: Alex's handler and a veteran MI6 agent. He is responsible for training Alex and providing him with instructions.
* Ian Rider: Alex's deceased uncle, who was also a secret agent and who inspired Alex to follow in his footsteps.
* Damian Cray: The main antagonist of the novel. He is a billionaire tech mogul who uses his company to control and exploit governments and individuals.
* Yassen Gregorovich: A skilled assassin and a recurring character in the Alex Rider series. He is hired by Damian Cray to eliminate Alex.
* The General: A mysterious figure who appears to be working with Damian Cray. He is a high-ranking military officer who controls access to Stormbreaker.
These are the main characters, but there are many other supporting characters who play important roles in the story.