Frederic Henry
The narrator and protagonist. An American lieutenant in the Italian ambulance corps who starts the novel as a detached drifter and slowly becomes someone with something to lose. His arc is a movement toward love and then into devastating loss. He is not a hero in any traditional sense — he deserts, he survives, and he ends up alone.
Catherine Barkley
A British nurse who has already lost her fiancé before the novel begins. She is sharp, self-aware, and emotionally honest in ways Frederic is not. She becomes the emotional center of the novel. Her death at the end is not a plot twist — Hemingway signals it throughout — but it is the blow the whole book is building toward.
Rinaldi
Frederic's Italian surgeon friend and the person who introduces him to Catherine. Rinaldi is charming, cynical, and uses drinking and women to survive the war. By the time Frederic returns to the front, Rinaldi is showing signs of breakdown — his coping strategies are failing. He represents one version of what the war does to men.
The Priest
A young Abruzzese priest attached to Frederic's unit who is mocked by the other officers but respected by Frederic. He represents faith and the possibility of a life with clear values — something Frederic cannot access but clearly envies. He and Frederic have some of the novel's most honest conversations.
Count Greffi
An elderly Italian nobleman Frederic plays billiards with in Stresa. He is nearly a hundred years old, worldly, and at peace with his life. He functions as a kind of mirror for Frederic — showing what a long life without illusions looks like — and their conversation touches on love, faith, and what people value when they are close to death.
Helen Ferguson
Catherine's fellow nurse and close friend. She disapproves of Catherine's relationship with Frederic, especially once Catherine becomes pregnant. She is loyal and protective, and her worry about Catherine turns out to be justified. She represents the practical, social consequences the two lovers are ignoring.