Bruno is a sheltered nine-year-old German boy whose life is uprooted when his father receives a promotion to a high-ranking military position. Accustomed to a comfortable life in Berlin, he is naive about the realities of World War II and the true nature of his father's work. He is naturally curious and enjoys exploring, though he struggles to understand the harsh adult world and the purpose of the fenced camp next to his new home.

Shmuel is a nine-year-old Jewish boy from Cracow, Poland, who shares an exact birthdate with Bruno. Wearing "striped pajamas" and an armband with a star, he is a prisoner in the camp adjacent to Bruno's new house. Despite experiencing the severe conditions of the camp, he retains a quiet resilience and speaks German well, which allows him to communicate with his new friend across the fence.

Bruno's Father is a stern, authoritarian Commandant in the Nazi army who is appointed by The Fury to oversee the camp at "Out-With" (Auschwitz). He is a World War I veteran who commands absolute obedience from his subordinates and his family. While he exhibits care for his children and provides for his household, he is simultaneously a ruthless orchestrator of the military operations within the camp.

Mother is a German woman who tries to maintain the appearance of a normal, aristocratic family life despite the terrifying realities of her husband's career. She outwardly supports his promotion but privately struggles with the isolation and bleakness of their new environment. Her growing unease is masked by a reliance on medicinal sherries and afternoon naps.

Gretel is Bruno's twelve-year-old sister. She is highly susceptible to the ideological influences around her, quickly abandoning her childish dolls to track the war's progress with push-pin maps. She behaves condescendingly toward Bruno and tries desperately to act like a mature adult, particularly around the young soldiers stationed at the house.

Lieutenant Kotler is a nineteen-year-old soldier serving as a direct assistant to Bruno's Father. Tall, blond, and meticulously dressed, he embodies the Aryan ideal but exhibits a casual, frightening cruelty toward the camp prisoners. He is arrogant, easily angered, and an imposing presence in the household.

Pavel is an elderly Jewish prisoner who is forced to work as a waiter and kitchen servant in the Commandant's home. Before the war and his internment in the camp, he was a practicing doctor. Frail and trembling, he demonstrates quiet kindness by tending to Bruno's scraped knee, representing the tragic loss of humanity and professional status inflicted by the regime.

Maria is the family's quiet maid who followed them from Berlin to "Out-With." Because Bruno's Father paid for her own mother's medical care and funeral during a time of extreme poverty, she feels deeply indebted to him. She keeps her head down and avoids expressing political opinions, warning Bruno to do the same.

Nathalie is Bruno's grandmother and a former singer. A free-spirited and artistic woman, she is fiercely opposed to the Nazi regime and refuses to be intimidated by the political climate. She publicly condemns her son's military uniform and his role in the war, leading to a bitter rift within the family.

Matthias is Bruno's grandfather. Unlike his wife Nathalie, he expresses immense pride in his son's promotion to Commandant. He actively supports the German war effort and the new regime, causing deep ideological friction in his marriage.

Herr Liszt is the strict, nationalistic tutor hired to educate Bruno and Gretel at "Out-With." He insists on teaching history and geography instead of the arts, utilizing his lessons to instill propaganda and a belief in the German "Fatherland" into the children.

"The Fury" is Bruno's misinterpretation of the title Führer (Adolf Hitler). He is the dictatorial leader of Germany who visits the family's home in Berlin to personally appoint Bruno's father to his new position. Bruno finds him deeply abrasive and unpleasant to be around.

Eva is the tall, beautiful, and blond companion of The Fury. In contrast to her partner's harsh demeanor, she displays a brief moment of conversational kindness toward Bruno and Gretel during her visit.