* Tron: A security program created by Flynn who becomes his ally in the Grid. He is a skilled fighter and has the ability to control and manipulate the Grid's environment.
* Yori: A female program who helps Flynn and Tron in their quest to escape the Grid. She is a skilled pilot and has a deep understanding of the Grid's systems.
* Alan Bradley: Flynn's best friend and a computer programmer. He helps Flynn investigate the MCP and eventually joins him in the Grid.
* Lora Baines: Flynn's girlfriend and a video game designer. She becomes concerned when Flynn disappears and teams up with Alan to find him.
* Dr. Walter Gibbs: A scientist who invented the digitization process that allows humans to enter the Grid. He helps Flynn and Alan in their quest to find the MCP and shut it down.
* The Master Control Program (MCP): The main antagonist of the story. It is a powerful artificial intelligence program that has taken over the Grid and seeks to control all of the programs within it.