Bill is a hardworking coal merchant and dedicated family man living in 1980s Ireland. Born to an unmarried domestic servant, he acutely feels his status as an outsider in a conservative Catholic society despite his current middle-class stability. He demonstrates a generous temperament, often giving money to the needy and employing local immigrants. A sense of curiosity and empathy drives his daily interactions, though he remains quietly troubled by the mystery of his father's identity.

Eileen is Bill's pragmatic and organized wife. She left her office job at Graves & Co upon marriage to raise their family and manage their domestic life. Highly conscious of social standing, she believes in conforming to the town's expectations and staying on the good side of powerful religious figures to protect her daughters' futures.

The Mother Superior is the tall, formidable woman who manages the Good Shepherd nuns' convent and its adjoining commercial laundry. She wields immense power over the local institutions, including the school attended by the Furlong daughters. She uses a mixture of false hospitality, subtle intimidation, and financial incentives to control what happens inside and outside her convent walls.

Sarah is Bill's late mother, who worked as a domestic servant in a Protestant household. Becoming pregnant outside of marriage at age 16, she faced social stigma and alienation from her own Catholic family. She raised her son under her employer's protection, keeping the identity of his father a closely guarded secret.

Mrs. Wilson is a wealthy, Protestant widow who lives in a large aristocratic house outside of town. She ignores the rigid moral codes of mid-century Catholic Ireland by allowing her pregnant teenage employee to keep her job and raise her child on the estate. She serves as a surrogate parent to young Bill, encouraging his education and providing him with the financial means to start his adult business.

Ned is the long-serving farmhand who works on Mrs. Wilson's estate. He serves as a steady, paternal presence in young Bill's life, teaching him practical skills like tying his shoelaces and shaving. He maintains the household's protective fictions regarding Bill's parentage, encouraging rumors that a wealthy visitor might have fathered the boy.

Kathleen, Joan, Sheila, Grace, and Loretta are Bill and Eileen's children. They are bright, well-behaved students who attend St. Margaret's, the only good girls' school in town. Their presence acts as a constant reminder to their parents of the need to maintain a respectable social standing in the community.

Mrs. Kehoe is a hardworking café owner who provides a regular lunch spot for the local laborers. She stays closely attuned to the town's gossip and social dynamics. Understanding the rigid power structures of New Ross, she adheres strictly to local Catholic traditions, such as serving fish and chips on Fridays.

Sarah is a teenage mother interned at the convent's Magdalen laundry. Separated from her 14-week-old son, she endures severe physical and psychological neglect under the nuns' care. The convent assigns her the male name Enda and attempts to dismiss her captivity as the result of mental confusion.