Eliot is the 46-year-old heir to the Rosewater fortune and a veteran of World War II. Disillusioned with his family's elitist worldview, he relocates to Rosewater, Indiana, to operate a crisis hotline from a dingy attic office, distributing his money to the impoverished. He is fiercely compassionate, though his unconventional behavior, heavy drinking, and intense empathy lead his family to question his mental stability.

Norman is a 23-year-old junior lawyer of Lebanese descent who works at the prestigious law firm of McAllister, Robjent, Reed, and McGee. Highly intelligent but lacking a moral compass, he feels ostracized by his wealthy, Anglo-Saxon colleagues and eats lunch alone. He discovers a legal loophole regarding the mental fitness of the foundation's president and plots to redirect the funds to an heir he can easily manipulate.

Lister is an influential politician from Indiana and Eliot's father. Having inherited his immense wealth, he firmly believes in free-market capitalism, self-reliance, and the inherent superiority of the rich. He views poverty as a character flaw and is deeply bewildered and frustrated by his son's charitable efforts toward the working class.

Fred is an insurance salesman living in Pisquontuit, Rhode Island, representing a less affluent branch of the Rosewater family tree. Burdened by financial struggles, an unhappy marriage, and the legacy of his father's suicide, he contemplates ending his own life daily. He is entirely unaware of his potential claim to an $87 million fortune until a lawyer arrives with a scheme.

Kilgore Trout is a prolific but largely unknown science-fiction writer who works as a stock clerk to survive. His speculative novels deal with dystopian futures, human obsolescence, and the ethical implications of a mechanized society. Though he operates on the fringes of the literary world, his philosophies heavily influence Eliot's worldview.

Sylvia is Eliot's wife, a French woman hailing from a family of wealthy cultural elites. She initially shares Eliot's philanthropic spirit and moves with him to Rosewater, Indiana. However, the emotional toll of serving the desperate townspeople severely impacts her mental health, leading to multiple breakdowns and an eventual attempt to distance herself from his mission.

Harry is a boisterous, physically imposing trap fisherman and the Chief of the Pisquontuit Volunteer Fire Department. A former insurance salesman who returned to the manual labor of his father, he presents an image of rugged, traditional masculinity. Despite his proud exterior and strong work ethic, he struggles financially in a rapidly modernizing economy.

Thurmond is the elderly senior partner at McAllister, Robjent, Reed, and McGee. He helps manage the massive Rosewater estate and works closely with Senator Lister to protect the family's assets. He firmly believes in the established capitalist order, viewing radical philanthropy as a destructive force that ruins both the donor and the poor.

Diana is a 68-year-old woman who works as a maid at the Rosewater mansion and lives a lonely, unhappy life. She relies heavily on Eliot's foundation for emotional support, frequently calling him to stave off her suicidal thoughts. She views Eliot as a saintly figure who brings comfort to the marginalized people of the town.

Dr. Brown is a psychiatrist who treats members of the Rosewater family. He authors a confidential treatise detailing Sylvia's condition, coining the satirical term "samaritrophia" to describe her overwhelming empathetic collapse. His diagnosis represents the medical establishment's tendency to pathologize extreme altruism.

Caroline is Fred's wife, a woman who married him under the mistaken belief that all residents of Pisquontuit were wealthy. She is deeply dissatisfied with their modest lifestyle and frequently socializes with her affluent friend Amanita to feel a sense of status and superiority.

Lila is the thirteen-year-old daughter of Stewart and Amanita Buntline. Highly entrepreneurial and cynical for her age, she secretly procures and sells pornographic material to locals in her Rhode Island town, demonstrating an early grasp of supply, demand, and commerce.

Amanita is a wealthy woman living in Pisquontuit. She enjoys flaunting her affluence and participating in the superficial social rituals of the upper class, often treating her less wealthy companion Caroline with subtle condescension, such as gifting her useless luxury items.

Stewart is a handsome heir to a $14 million fortune whose only real passion is studying the Civil War. Years ago, his lawyer convinced him to abandon his philanthropic urges, leaving him a politically conservative but largely inactive and unfulfilled member of the wealthy elite.

Charley is the Fire Chief of Rosewater, Indiana, who also runs a local insurance office. He interacts with Eliot frequently, given Eliot's intense admiration for volunteer firefighters and obsession with preventing fires.

Selena is a maid working for the Buntline family, having come from an orphanage they founded. Required to take a weekly oath affirming her gratitude to her employers, she deeply resents the condescending nature of their charity and dreams of escaping to become a nurse.

Bunny is the owner of The Weir, a restaurant that houses an enormous private collection of harpoons. He gossips with the wealthy patrons and provides cynical commentary on the changing economy, notably explaining that physical laborers like Harry Pena are becoming obsolete.

Franklin is the young son of Fred and Caroline Rosewater. He is the primary reason Fred decides not to follow through with his daily suicidal ideation, providing his father with a crucial anchor to life.