Jake is an American expatriate and World War I veteran working as a journalist in 1920s Paris. He suffered a war wound that left him impotent, profoundly affecting his self-image and his romantic life. He frequently seeks distraction through alcohol, travel, and his deep passion for bullfighting.

Brett is a charismatic, fiercely independent woman moving through the post-war social scene in Europe. She refuses to adhere to traditional expectations of marriage and monogamy, instead shifting fluidly between various suitors. She genuinely cares for Jake but avoids committing to him because she desires physical intimacy.

Cohn is an American expatriate writer who differs from his peers because he did not serve in the war. He maintains a romantic worldview shaped by adventure novels and feels a sudden urge to escape his current life in Paris. He struggles with feelings of insecurity and often faces casual prejudice from his social circle.

Bill is a successful American author and World War I veteran. He uses humor, sarcasm, and heavy drinking to cope with the lingering effects of the war. He serves as a loyal and easygoing companion for Jake during their retreat into the Spanish countryside.

Mike is a Scottish war veteran and an undischarged bankrupt who evades his creditors across Europe. He frequently drinks to excess, using alcohol to manage his jealousy regarding Brett's interactions with other men. He displays a cruel streak when threatened, frequently directing his anger at easier targets.

Pedro is a nineteen-year-old bullfighter from a town near Gibraltar. He fights with exceptional grace, passion, and honesty, placing himself in genuine danger rather than faking close calls. He represents an idealized form of courage that Jake greatly admires.

Frances is an American woman living in Paris with Robert Cohn. She recognizes that she caught Cohn on the rebound and worries intensely about losing her youth and appeal. She treats her relationship with Cohn transactionally, expecting financial support.

Georgette is a Parisian sex worker who joins Jake for dinner. She is cynical about her life and health, sharing the post-war disillusionment common among the expatriates.

The Count is an older, wealthy man who takes an interest in Brett. He carries arrow scars from his youth in Abyssinia and claims that his past experiences allow him to fully enjoy the present, particularly fine food and wine.

Harvey is a broke American expatriate living in Paris. He spends his time drinking and gambling rather than working, relying on the occasional generosity of friends to survive.

Montoya is the proprietor of the Hotel Montoya in Pamplona. He respects true bullfighting aficionados and will forgive almost any poor behavior from those who genuinely appreciate the sport.

Harris is a polite English war veteran who shares Jake and Bill's love for fishing. He genuinely enjoys their company and provides a contrast to the transactional relationships seen in Paris.

Edna is a friend of Bill's from Biarritz who visits Pamplona during the festival. She acts as a cheerful companion and tries to diffuse the escalating tensions among the men.

Belmonte is a legendary bullfighter who has recently come out of retirement. He struggles to meet the impossibly high expectations set by his own past fame and is consequently jeered by the crowd.