In some ways Jess is a typical 10-year-old boy. He dislikes school, loves running, and struggles to find his own identity. Not typical, however, is that Jess is the "weird" kid who likes to draw, an activity that isn't viewed as manly by most people around him. Because Jess wants to fit in, he hides his love of art initially. He has many responsibilities at home and does chores to help feed his family, but he gets little thanks or even recognition for his work. Feeling alone in his family because he is the only boy and because his father is away most of the day, Jess longs for someone he can talk to, someone who can understand and help him through the bumps in life. Jess doesn't expect this person will be outsider girl Leslie Burke, but once they become friends, there is no stopping the transformative power of their relationship. Through Leslie Jess grows in courage and imagination and begins to believe in himself. He helps expand her world as well, for he accepts her just as she is, something their classmates do not.
Leslie moves from a wealthy suburban school to rural Lark Creek after agreeing with her parents to try a new lifestyle. Like her parents, whom she calls by their first names, Leslie has a talent for writing and a well-developed imagination. She is smart, independent, and curious and does not conform to society's dictates, especially gender expectations. She has very short hair, wears pants to school, and runs faster than any of the boys. In many ways Leslie seems more adult than child, though she still has much room to grow and mature. Her friendship with Jess exposes her to new experiences, like going to church, and feelings, such as compassion for an unappealing person like Janice Avery. While Leslie is a model of bravery to Jess, her fearlessness also leads to her death.
May Belle is a curious, sometimes lonely, little girl who idolizes her older brother and wants to be included in his friendship with Leslie. Jess often considers May Belle a nuisance, but he also enjoys the attention and has genuine affection for her. May Belle has friends at school, but it is Jess she longs to be close to. She often does small tasks for him and keeps his secrets. Over time she earns his trust and respect, waiting patiently until Jess is ready to welcome her fully into his inner circle of friendship and magic that exists in Terabithia.
Miss Edmunds is the picture of a 1970s hippie woman. A guitar-toting, peace-anthem-singing music teacher, she seems almost like a dream to students like Jess. Warmhearted, perceptive, and kind, she encourages Jess to pursue his art when no one else supports him or shows any interest. Miss Edmunds goes above and beyond what is expected of a teacher by taking Jess to visit museums in Washington, D.C. She knows his parents wouldn't dream of such an excursion and by expanding his world even a little bit, she can help Jess find the inspiration he needs to step outside of narrow social expectations and become the person he has the potential to be.
Called Dad and Daddy, Mr. Aarons lives a hard life, working from sunup to sundown to make ends meet. He must work at a full-time job off the farm because he, like other small farmers, cannot make enough money from the land. Even though he loses his job, he never gives up and finds ways to keep the family afloat. Affectionate with May Belle, and somewhat indulgent with Brenda and Ellie, he has different standards of behavior for Jess. He shows no physical affection toward his son for most of the story and expects him to act like "a man," shouldering many of the responsibilities of the family. He never praises Jess for his talents but does criticize him for his faults. Although Mr. Aarons can be gruff, he is softer at heart than he seems. When Jess really needs emotional support, Mr. Aarons is there without fail. Despite feeling awkward, Mr. Aarons breaks through his own standoffishness to hug and comfort his son after Leslie's death. He is able to treat him with compassion and see him again as a child, not yet a man, but still worthy of love and respect.
Mrs. Aarons's life is too exhausting to allow her much pleasure. She is usually working around the house and is harder on Jess than on the other children, often scolding or nagging him about chores, even though he is responsible about his work. Mrs. Aarons worries about money continually (since they rarely have enough) and doesn't want anyone to look down on her family. She struggles to clothe her children decently so they will look presentable to what she takes for society. Although Momma can be harsh at times, her genuine love for her children comes through, particularly when Jess goes into crisis. She is able to show him gentleness and compassion that previously have been missing in their relationship.
On the surface Janice Avery plays the stock character of the school bully, taunting and harassing anyone younger or weaker than she is. She takes their money, steals their lunch treats, and seems to relish the power of keeping others in fear. However, as the story progresses, Janice's character is revealed as more complex. She faces her own set of problems, from self-consciousness about her size to humiliation over her crush on Willard Hughes. Her troubles are darker than this, though: her father beats her. When needing comfort and sympathy, she shares this information with her two closest friends, who betray her by spreading the story around the school. Janice shows she is not above changing her ways when she accepts Leslie's friendship in the aftermath of this incident, even though they have been adversaries in the past.