Alfred is the 75-year-old patriarch of the Lambert family and a retired railroad engineer. Raised in the Depression-era Midwest, he values hard work and concrete physical reality over modern frivolities. His worsening Parkinson's disease and dementia make him increasingly dependent, though he maintains a gruff exterior that terrifies his adult children.

Enid is the 75-year-old matriarch of the Lambert family who has spent her life as a traditional Midwestern homemaker. She is deeply concerned with appearances and the lives of her neighbors in St. Jude. Highly anxious but optimistic, she desperately tries to corral her three adult children home for one last family Christmas while stubbornly denying the severity of her husband's declining health.

Chip is the middle Lambert child, a failed academic who lost his tenure-track position at a prestigious college following a scandalous affair with a student. Now an aging bohemian in New York City, he attempts to write a screenplay while sinking into debt. He represents a sharp divergence from his parents' Midwestern values, though his intellectual posturing masks a deep desire for his father's approval.

The oldest Lambert child, Gary is a highly successful bank executive living in a sheltered Philadelphia suburb. He is outwardly conventional and strives to correct his father's emotional stinginess by being excessively indulgent with his own children. Despite his material success, Gary is plagued by a pervasive fear that he is clinically depressed.

The youngest Lambert child and only daughter, Denise is a highly successful executive chef opening a trendy new restaurant in Philadelphia. She is fiercely independent and adept at working in high-pressure culinary environments. Underneath her professional polish, she struggles with her fluid sexuality and a history of seeking validation through complicated relationships with older or unavailable people.

Caroline is Gary's independently wealthy wife and a part-time pro bono lawyer. She utilizes permissive parenting strategies that contrast sharply with Gary's Midwestern upbringing. She wields Gary's fear of clinical depression against him as a means of maintaining control in their increasingly strained marriage.

Robin is Brian Callahan's wife, an earnest and principled woman from a lower-middle-class background who feels uncomfortable with her husband's new wealth. She is initially hostile toward Denise but gradually lowers her guard, drawn into an all-consuming affair with the chef.

Brian is a multimillionaire who acquired his wealth through stock options in a computer corporation. He is suave and worldly, serving as the financial backer for Denise's culinary ventures while remaining largely absent from his own marriage.

Gitanas is the former deputy prime minister of Lithuania and Julia's estranged husband. He is a charismatic and openly corrupt political figure who enlists Chip to help him defraud American investors. He offers Chip a chaotic but strangely honest alternative to the pretensions of the New York literary world.

Julia is Chip's New York City girlfriend and the estranged wife of Gitanas. She abandons Chip just as his parents arrive for a visit, citing her frustration with the inherent sexism of his sprawling screenplay.

Aaron is the oldest son of Gary and Caroline. Caught in the crossfire of his parents' marital battles, he is confronted by his drunken father during a disastrous family dinner regarding his mother's claims about Gary's mental health.

Caleb is the middle son of Gary and Caroline. Enabled by his mother's permissive parenting style, he lobbies to install a surveillance system in the family kitchen, much to his father's traditional Midwestern dismay.

Jonah is the youngest son of Gary and Caroline. He becomes a pawn in his parents' underground war when Caroline plies him with a new video game to ensure he does not travel to visit his grandparents.

Sylvia is a wealthy and sheltered intellectual who travels on the same cruise ship as Alfred and Enid. Despite her moneyed sophistication, she carries a profound trauma from the murder of her only daughter, which she processes through a newfound fascination with guns and vengeance.

Don is a Vietnam veteran who expects to lose his job in an impending corporate takeover. He seduces a teenage Denise during her summer job, an illicit encounter that complicates her family's history.

Melissa is a worldly and manipulative college student. She seduces Chip, convinces him to take a road trip, and plies him with drugs before abruptly abandoning him to meet her parents, an event that destroys his academic career.

Bea is the Lamberts' wealthy neighbor in St. Jude. For years, she serves as an object of Enid's deep jealousy regarding her picture-perfect family, representing the conventional Midwestern success Enid craves.

Chuck is a banker and the Lamberts' neighbor in St. Jude. He becomes wealthy thanks to an insider tip about a railway merger casually provided by Alfred years ago, a fact that deeply rankles Enid.

Emile is a middle-aged Jewish chef from Montreal and Denise's former husband. Their short-lived marriage and subsequent divorce remain a point of bitter contention between Denise and her mother.

Billy is Robin's adopted brother who terrorized her during their youth. He eventually goes to prison for assaulting a corporate vice president linked to Brian Callahan's wealth.

Eden is an upscale film producer in New York City and Julia's boss. Chip desperately tries to sell her his screenplay, convinced that catering to her specific notes will save him from financial ruin.

Dr. Schulman is a young medical professional who attends to Alfred's complex neurological and physical needs at his nursing home. She proves to be a competent and calming presence for the Lambert patriarch and quickly catches the attention of his son.

Sinéad is one of Robin and Brian's two daughters. She becomes attached to Denise as the chef spends increasing amounts of time at their home during the affair.

Erin is Robin and Brian's other daughter. Along with her sister, she is drawn into Denise's life when the chef begins an intense relationship with their mother.