Jimmy Hopkins/Gary Smith IV

Jimmy is a 15-year-old teenager, of robust build and very short in stature compared to the other students, he is even shorter than the other students. He is approximately 1.65 meters tall, reasonably robust, blond, with brown eyes and freckles on his cheeks. He also has a reddish nose and a gold earring in his left ear. Jimmy can be seen with very short hair, though not completely shaved, and wears a brown jacket over a white t-shirt, blue jeans, and white sneakers. His school uniform consists of a blue Bullworth vest over a white shirt, khaki pants, and the same sneakers he wears upon arrival. Jimmy isn't a particularly muscular student, but he's not weak either. Despite having a body lacking muscle mass, he compensates with his inexhaustible energy, which allows him to sprint without tiring, have the agility to climb walls, and also to fight. Jimmy has the typical personality of a reckless schoolboy who doesn't care about anything or anyone but himself. He's not usually violent; in fact, he only resorts to violence when challenged to a fight. He does have a good side, as he helps those in need, although most of the time he demands something in return (money or objects).

Jimmy is dropped off at Bullworth Academy by his mother, who frequently remarried, and his new stepfather, whom Jimmy describes as a "rich old phony." Afterward, they go on their honeymoon. Jimmy has already been expelled from seven schools for reasons such as violent behavior, graffiti, disrespect toward authority, and using foul language. Bullworth is Jimmy's last chance to avoid being sent to a juvenile detention center. Jimmy isn't a bully; he fights against those who abuse others. His mother leaves him at Bullworth Academy after marrying a wealthy man, and the headmaster warns him it's his last chance before facing juvenile detention. He's a skilled fighter, especially after learning various fighting techniques from a homeless man. He also has talents in painting and photography. One of Jimmy's most remarkable qualities is his courage and fearlessness. He possesses great talent and skill in karate, wrestling, and boxing. He received karate training from a Korean War veteran.

Gary is slightly taller than Jimmy, but a bit thinner. He has brown hair parted on the left, brown eyes, and a noticeable scar above his right eye. He wears a teal Bullworth waistcoat, which is exclusive to him, over a white shirt and grey school trousers. He wears a silver watch on his left wrist and a brown leather bracelet on his right. On Halloween, he dresses up as a Waffen-SS commander and carries a riding crop, which Jimmy can snatch from him. In winter, Gary rolls down his sleeves and adds a navy blue winter hat with a black stripe to his usual outfit. Gary has a very bad reputation among the students and even the school staff.

Pete is the shortest of all the older students, shorter than Jimmy and even most of the students who aren't part of the group. He wears the same blue Bullworth vest as Jimmy, with a pink shirt underneath and brown school uniform trousers. In winter, he wears black trousers and maroon gloves. He has very short, dark brown hair and brown eyes. His best friend is Jimmy, and the friendship is mutual, as Pete is also Jimmy's only friend. Pete Kowalski, whose full name is Peter and who is also known as Petey, is a main character and deuteragonist in Bully. He also claimed to be from Bullworth Town and that his parents forced him to go to the Academy because it was the only boarding school within walking distance of their home and they needed "peace and quiet at home." He was described as a "normal kid" who liked watching television and playing video games, but he also admitted to liking art. Very little is known about Pete's home life, and his most defining personality traits are shyness and awkwardness, rather than being an average person. In his own words: "I'm too cool to be a nerd, and too nerdy to be anything else." Pete's bisexuality or homosexuality is implied by his pink shirt and a terribly awkward joke he makes during Chapter 4, suggesting that Jimmy would make a good stripper. Gary also mocks him, referring to him as a "faggot" and asking if he's watching the swim team for the girls or the boys, and Gordon spreads the rumor that he has a crush on Jimmy. However, he did show interest when Jimmy jokingly offered to find him a girlfriend. He will yell "Now I'll never be a dad!" if he gets punched in the groin, and he is also condemned to remain a virgin forever. He also wears a pink bunny costume on Halloween, but only after Gary forces him to.

Though physically unassuming, Pete is extremely intelligent and possesses a brilliant mind for strategy. After Gary's betrayal, Pete begins acting as Jimmy's advisor. His advice proved invaluable in Jimmy's campaign against the Preps and the Nerds. He also convinces Jimmy not to give up after Gary gets him expelled. Algie tells him he might not be able to join the Nerds because they consider him "weird." Due to his short stature, Gary, among others, mercilessly teases him. He's unhappy with his size and lack of physical ability and wants to take karate lessons. He claims his father is a librarian and seems embarrassed by it. His lack of physical fitness might be hereditary. He's said to suffer from asthma, which could also contribute to his lack of athleticism.

Throughout the game, Jimmy establishes relationships with various characters, such as his friend Pete Kowalski, who is a victim of bullying, and Gary Smith, who helps him from time to time.