Gregor is a young traveling salesman who has spent the past five years working a grueling job to support his parents and sister. He hates the constant travel and poor diet required by his position but pushes through to pay off his father's debts. Despite his sudden physical transformation into an insect-like creature, his mind remains human. He focuses heavily on his work responsibilities and his family's financial well-being rather than his own bizarre physical reality.

Grete is Gregor's 17-year-old sister and the only family member who shows immediate practical concern for his wellbeing following his transformation. She assumes the role of his primary caretaker. She brings him various foods to discover his new preferences and modifies his room to better suit his physical shape. Before the change, she lived a somewhat sheltered life focused on her violin studies.

Mr. Samsa is Gregor's father. He has been unemployed and sedentary for five years following the collapse of his own business. He relies entirely on Gregor's income to support the household and pay off his outstanding debts. He responds to disruptions in his home with immediate hostility and physical aggression.

Mrs. Samsa is Gregor's mother, defined by her gentle nature and her severe asthma. She makes excuses for Gregor when his manager arrives, defending him as a dedicated worker who cares only about the business. Her maternal love for Gregor conflicts directly with her intense physical revulsion at his new appearance.

The manager represents the strict, unforgiving nature of Gregor's employer. He visits the Samsa apartment personally the moment Gregor fails to catch his usual train. He quickly accuses Gregor of neglecting his duties, withholding cash collections, and generally lacking a strong work ethic.

The head of the company where Gregor works as a traveling salesman. Though he does not appear directly in the apartment, his authority looms heavily over the Samsa household. He holds a financial debt over Mr. Samsa's head, which forces Gregor to remain in a job he despises.

Anna is the Samsa family's live-in kitchen maid. When the reality of Gregor's condition becomes apparent in the household, she begs Mrs. Samsa for permission to be released from her employment.

A large, bony woman hired to clean the apartment after the family downsizes their staff. Unlike the rest of the household, she is completely unbothered by Gregor's appearance. She speaks to him casually and checks on him directly.

Three serious men who rent rooms in the Samsa apartment. They are extremely particular about cleanliness and expect excellent service from the family. Their arrival forces the family to use Gregor's room as a storage space for unwanted furniture.