Jesse Aarons Jr.
Played by: Josh Hutcherson
- Big Brother Instinct: Towards May Belle.
- Guilt Complex: He didn't tell Leslie about the trip to the museum because he wanted to alone with Ms. Edmunds. If he had not done this, Leslie may not have died.
- Heroic B.S.O.D.: Suffers an extremely realistic one after Leslie's death.
- Masculine Girl, Feminine Boy: He's an artistic boy who tries to not let his many insecurities get the best of him while Leslie is a runner who uses her sense of adventure to design an imaginary kingdom across the creek.
- Outnumbered Sibling: He is the only male in the Aarons siblings.
- The Protagonist: The story focuses mostly on him, and he goes through most of the character development.
- Teacher/Student Romance: He has a one-sided crush on Ms. Edmunds.
Played by: AnnaSophia Robb
- Death by Irony: She was a good swimmer.
- Dropped a Bridge on Him: Before there even was a bridge.
- Killed Offscreen: Jesse just finds out that she died after coming home from the museum.
- Kill the Cutie: Thankfully, off-screen. Not that it makes it less saddening.
- Knight of Cerebus: Inverted, she is one of the lightest and nicest characters in the book, but the book takes a darker turn with her death.
- Hippie Parents: At least compared to the other parents in the story.
- Lady Looks Like a Dude: When Jesse first met her in the novel, he thought she might have been a boy because of the way she dressed and her short hair, as well as having a name that some boys have.
- Masculine Girl, Feminine Boy: She's a runner who uses her sense of adventure to design an imaginary kingdom across the creek while Jess is an artistic boy who tries to not let his many insecurities get the best of him.
- Nice Girl: She is friendly to everyone she meets, and even reaches out to Janice Avery.
- One of the Boys: Leslie's first friend is a guy, and it is implied that she doesn't have any others. Jess befriends and spends time with her to get away from his girly-girl sisters, despite the fact that she's a girl as well.
- Tomboy and Girly Girl: The Tomboy to May Belle's Girly Girl
May Belle Aarons
Played by: Bailee Madison
- Annoying Younger Sibling: She can be this to Jesse
- Big Brother Worship: Can also be seen as this to Jesse.
- Tomboy and Girly Girl: The Girly Girl to Leslie's Tomboy
Joyce Ann Aarons
Played by: Grace Brannigan
- Annoying Younger Sibling: Her siblings consider her a whiny brat.
Played by: Zoey Deschanel
- Cool Teacher: That plus her looks is what Jesse likes about her.
- Unwitting Instigator of Doom: Had she not called Jesse to join her at the museum, Leslie would probably have survived her last trip to Terabithia.
Played by: Emma Fenton
- Bratty Teenage Daughter : Both the older daughters are this.
Played by: Devon Wood
Played by: Lauren Clinton
- Abusive Parents: Her father physically abuses her.
- Freudian Excuse: See Abusive Parents.
- Heel–Face Turn: After Leslie reaches out to her. She even beats up another bully for messing with Jess after Leslie's death.
Played by: Robert Patrick
Played by: Kate Butler
Played by: Latham Gaines
Played by: Judy McIntosh
Gary Fulcher and Scott Hoager
- The Bully: Toward Jess, and Leslie's death does nothing to stop them.
- Catch Phrase: Gary always calls Jess "Dead Meat". In Terabithia, this is translated in the form of a hairy vulture that's constantly squawking "DEAD MEAT!"
- Decomposite Character: They where the same character in the book, but Scott Hoager is a character made up in the movie.