Frederic Henry An American second-lieutenant in the ambulance corps of the Italian army during World War I.
Catherine Barkley A British nurse who falls in love with Henry following the death of her fiancé in battle.
The Priest The chaplain in Henry's unit. Baited by the other officers, he is befriended by Henry, to whom he offers spiritual advice.
Rinaldi Henry's roommate and friend, an Italian lieutenant and surgeon.
Helen Ferguson Catherine's friend and fellow nurse.
Passini and Bonello Ambulance drivers serving under Henry.
Manera, Gavuzzi, Gordini, Piani, and Aymo Other ambulance drivers.
Mrs. Walker An American nurse at the hospital in Milan.
Miss Gage Another American nurse, sympathetic to Henry and Catherine's affair.
Miss Van Campen The hostile superintendent of nurses.
Dr. Valentini A highly competent Italian surgeon, full of joie de vivre.
Meyers A somewhat sinister American expatriate.
Ettore Moretti An Italian-American from San Francisco serving with distinction in the Italian army.
Ralph Simmons An American student of opera and a friend to Henry.
Count Greffi An aging but vigorous Italian who befriends Henry in Stresa and serves as a mentor to him.