Bigger Thomas is a 20-year-old black man living in extreme poverty in a segregated section of Chicago's South Side. He has few opportunities to improve his life, even if he felt motivated to do so. In his relationships with his friends and family, he is driven by a deep fear of being thought weak. In his relationships with white people, he is driven by a deep fear of punishment. These fears cause him to act out in violent and dangerous ways that ultimately cause his downfall.
The only child of Henry Dalton and his wife, Mary Dalton talks freely to Bigger about his rights as a worker but is happy to take advantage of the benefits of her parents' wealth. At the same time, she actively rebels against her parents' values through her romantic attachment to Jan, a well-known communist. When Bigger is hired, she convinces him to drive her and Jan during a night out on the town that ends with her accidental death at Bigger's hands.
Jan Erlone is a member of the Communist Party and Mary Dalton's lover. He attempts to educate Bigger about his rights as a worker and bring him into the party. After Mary is killed, Bigger attempts to frame Jan for the murder, but when the truth comes out Jan forgives Bigger, believing Bigger's own poverty and lifelong experience with prejudice have made him a victim as well.
Bessie is Bigger's "girl," and the two have sex on a regular basis. She drinks heavily to cope with her life of hard labor as a domestic servant. While it is not clear whether she truly loves Bigger, she seems to find comfort in his company, and she has helped Bigger pull off small robberies of some of her employers. Bigger enlists her to help with his attempt to get ransom money from the Daltons, but she is overcome by her fear of Bigger and of the police, leading to her murder at Bigger's hands.
Jan brings Boris Max onboard as Bigger's defense attorney after he is arrested and indicted for the murders of Mary and Bessie. Like Jan, Max sympathizes with Bigger and understands the ways poverty and racism have shaped Bigger's actions and personality. He is the first and only person Bigger trusts enough to have truly honest conversations about his life and circumstances.
Mrs. Thomas is Bigger's mother. She loves her son but finds herself in almost constant conflict with him. She wants him to get a job, help provide for the family, and join her at church, yet he resists her at every turn. When he is arrested and her worst fears about her son come true, she remains supportive and loving toward him.