Eddie is a 40-year-old longshoreman who lives in the Red Hook neighborhood of Brooklyn. He works hard physical labor on the piers to support his wife, Beatrice, and his niece, Catherine, whom he has raised since childhood. Eddie adheres to a strict, traditional code of masculinity and community loyalty, taking pride in his role as a provider. However, his unacknowledged, obsessive attachment to his niece clouds his judgment and drives his hostility toward her new suitor.

Beatrice is Eddie's dedicated wife and Catherine's aunt. Though Eddie frequently dismisses her insights because she spends her time as a housewife, she possesses sharp emotional intelligence and clearly perceives the changing, dangerous dynamics in her home. She is generous, organizing the safe harbor for her undocumented cousins, but she increasingly pushes back against Eddie's controlling nature.

Catherine is the 17-year-old niece of Beatrice and Eddie, raised in their home as a surrogate daughter. She is on the cusp of adulthood, having just been offered a job as a stenographer. Sheltered by Eddie for her entire life, she is initially naive and eager to please him, but she soon begins seeking her own autonomy and romantic independence.

Rodolpho is Beatrice's younger cousin, an undocumented immigrant who travels from Italy to New York seeking economic opportunity. Unlike his stoic brother, Rodolpho is expressive, blonde, and highly sociable. He hopes to save enough money to buy a blue motorcycle and enjoys singing jazz, cooking, and making dresses—traits that deeply upset the traditional gender expectations of his host.

Marco is Beatrice's older cousin and an undocumented immigrant. He has left a starving wife and three children in his Italian hometown and comes to America solely to earn money to send back to them. Described by his fellow workers as a "regular bull," Marco is immensely strong, quiet, and deeply respectful of the laws of hospitality, though he will silently assert his dominance to protect his younger brother.

Alfieri is a middle-aged, first-generation Italian American lawyer working in the working-class neighborhood of Red Hook. He functions as a bridge between the old-world values of the Sicilian immigrants and the official laws of the United States. He watches the events of the play unfold, acting as a narrator who understands the tragedy brewing in the Carbone household but remains powerless to stop it.

Louis is a longshoreman who works alongside Eddie at the Brooklyn waterfront. He represents the broader neighborhood community and casual working culture. He frequently observes the newcomers, Marco and Rodolpho, sharing his impressions of their work habits with Eddie.

Mike is another longshoreman working the piers with Eddie. He casually praises Marco's incredible physical strength and remarks on Rodolpho's habit of making the crew laugh, innocent observations that inadvertently feed into Eddie's growing resentment.

Lipari is the local butcher in the Red Hook neighborhood. He and his wife are part of the tight-knit immigrant community that strictly adheres to unwritten codes of mutual protection and silence regarding undocumented residents.

Vinny is a local teenager who serves as a severe cautionary tale for the Carbone family. After reporting his own uncle to immigration services, he was violently beaten by his brothers and permanently ostracized by the neighborhood, illustrating the severe consequences of breaking the community's code of silence.