Known to readers as William Shakespeare, the Latin tutor is Agnes's husband and the father of her children. He starts as an unremarkable family man in Stratford but becomes a famous playwright in London, leading a double life between his family and his career.

Hamnet is the eponymous protagonist, an 11-year-old boy who shares attributes with his father, such as intelligence and a tendency to dream. He has a close bond with his twin sister Judith and loves his mother deeply.

Judith is Hamnet's twin sister, characterized as delicate and introverted. She is close to Hamnet and is deeply affected by his death, finding solace in caring for cats.

Susanna, the eldest child of Agnes and the Latin tutor, is dutiful and practical, responsible for maintaining the household. She struggles with her parents' differing needs and desires stability for herself.

Joan is Agnes’s stepmother, a practical and cynical woman suspicious of Agnes's supernatural abilities. She resents Agnes and harbors ill feelings, relishing in Agnes's misfortunes.

Bartholomew is Agnes’s brother, a large man devoted to his sister's well-being. He supports Agnes's family and balances his earthy nature with the more restless qualities of Agnes's husband.

John, the Latin tutor's father, is a disgraced glove merchant with a harsh demeanor. His relationship with his son is strained, and he is a figure of fear for his grandson Hamnet.

Mary is John's wife, stern but maternal, with eight children, three of whom died. Initially wary of Agnes, she grows to respect her daughter-in-law and helps care for their family in times of need.

Eliza is the Latin tutor's sister, literate and independent-minded. She is supportive of Agnes and her brother's family while seeking her own stability through marriage.

The Manx cabin boy appears in Chapter 11 of *Hamnet*. He parallels Hamnet in his youth and innocence, offering a contrast to Hamnet's fate as he survives the plague-ridden ship and returns home with a cat.