Curtis
Curtis is the leader or the revolution. He is a tail passenger who has long resented Wilford's corrupt leadership and is determined to lead a violent revolt to help tail passengers make their way to the front of the train and overthrow Wilford. Late in the film, we learn he nearly ate his second in command and friend, Edgar, when Edgar was a baby, and that he feels a great deal of guilt about this. His mentor, Gilliam, tells him time and time again that he would make a great leader, but Curtis does not himself believe this. When he meets Wilford at the end, Wilford reveals that Gilliam and he were co-conspirators and offers Curtis the opportunity to become the new conductor of the train. Intent on doing what is right, Curtis declines and chooses to blow a hole in the train and put a stop to the corrupt society onboard. Curtis is heroic, serious, and self-sacrificing, and must engage in some horrible violence in order to do what is best for his fellow tail passengers.
Wilford
Wilford is the conductor of the train, a calm and ingratiating leader, who wears a robe and eats steak in his luxurious front car. While he uses child labor to run the car and kills his less wealthy passengers to maintain the class hierarchy on the train, he believes that what he is doing is benevolent. He is the prototypical image of a fascist dictator, a powerful figurehead who is cocooned from the violence and destruction he creates.
Gilliam
Gilliam is the elder of the tail section, a mentor to Curtis, grooming him to become the leader of the revolution to free the people from the horrific conditions of the train. In a devastating twist, we learn that he has been in league with the evil Wilford for years, and that his helping Curtis is only part of Wilford's plan.
Minister Mason
Minister Mason is second in command to Wilford on the train, a spokesperson and hype-woman for the evil leader. When the film begins, she has worked for the last 17 years disseminating propaganda to make Wilford look good. She pummels the rear section with abuses to ensure they are in line with what is expected of them. Curtis executes her after Gilliam is killed. She is cowardly and ridiculous in her undying loyalty to Wilford.
Edgar
Edgar is Curtis' best friend. Curtis reveals that when Edgar was a baby, he was ready to eat the infant for food, but Gilliam stopped him by offering his arm in exchange. Edgar follows Curtis into battle and is a true believer in Curtis' cause, if less brave and resourceful than his friend. When Curtis is given the chance to save Edgar during an ambush, he does not, as he knows if he does he won't be able to move forward. Thus Edgar is killed.
Namgoong Minsu
Namgoong Minsu is a security expert on the train. He designed the security features and has been arrested and put into a deep sleep along with his daughter. Curtis and his companions awaken Nam in order to get his help opening the doors to the cars that lie ahead. He has become a drug addict, addicted to Kronole, and Curtis must give him a hallucinogen in order to get him to stay focused. He detonates a bomb that destroys the train.
Yona
Yona is Nam's daughter, a fellow Kronole addict and clairvoyant. Her prophetic abilities allow her to tell the revolutionaries what is waiting on the other side of various gates on the train. She ends up surviving the train crash and wanders into the snow with the young boy, Timmy, looking for signs of life.
