Tom Sawyer
The protagonist. Tom is imaginative, manipulative, and desperate for admiration. He drives every major plot event—the island runaway, the courtroom testimony, the cave escape. His arc is about learning that real heroism requires risk, not just performance.
Huckleberry Finn
Tom's best friend and the town outcast. Huck is free from adult supervision but also poor, lonely, and looked down on. He witnesses the murder with Tom and shares the burden of the secret. He represents the cost of living outside society's rules.
Aunt Polly
Tom's guardian and the moral center of the book. She disciplines Tom but loves him fiercely. Her grief during the island runaway is the moment that most clearly shows Tom the human cost of his stunts.
Injun Joe
The novel's villain. He commits the murder, frames Muff Potter, and hunts for revenge. He functions as the dark mirror of Tom—another outsider who operates outside the rules—but chooses violence where Tom eventually chooses honesty.
Becky Thatcher
Tom's love interest and the judge's daughter. She is brave enough to share blame with Tom during the school punishment scene, and her presence in the cave forces Tom to be genuinely heroic rather than just theatrical.
Muff Potter
The drunk who gets framed for the murder. His imprisonment is the source of Tom's guilt and the reason Tom eventually testifies. He represents the innocent person who suffers when bystanders stay silent.
Sid Sawyer
Tom's half-brother and the model student. Sid follows every rule and reports Tom's misbehavior to Aunt Polly. Twain uses him to show that rule-following without genuine goodness is just self-serving tattling.