A common theme in the work of Ernest Hemingway is gender dynamics, femininity, and masculinity. In his epic For Whom the Bell Tolls, these themes are pervasive. The novel takes place during the Spanish Civil War and follows a group of rebellious guerilla fighters that include both men and women.

When the novel's protagonist, Robert Jordan, begins a sexual relationship with Maria, a young woman who had her head shaved after being raped by a gang of fascists, she is frequently objectified by Jordan as a sexual object. When she is unable or unwilling to perform sexual acts with him, he becomes frustrated and wholly disappointed. While he pretends to be satisfied with lying near her and conversing, his disappointment is evident, thus suggesting his categorizing her as a sexual being.

Pilar, the heroic and headstrong female leader/maternal figure of the rebellious guerrilla group, often is criticized by Maria and the men for possessing traits they consider masculine. "Why do you speak in such a brutal manner," Maria says to her in one passage (140). In another passage, Pilar says to a male member of the group, Primitivo, "Thou must act like a man," (299). This reinforces the gender roles set about and questioned by Hemingway. In these roles, women are not meant to be brutal, while men are not meant to be delicate. The men speak crudely to Pilar, "thou hast the tongue of the great whore!" (383).

Even though Hemingway certainly seems aware of the sexist overtones of For Whom the Bell Tolls, it becomes difficult to classify the novel itself as sexist, particularly because of the questioning of these dynamics. Pilar is often criticized for not being feminine, yet she continues in her crude ways, often bullying some of the men. Maria is sexualized by Robert Jordan, but after they have sex, these dynamics are questioned. She finds power in her sexuality, and she finds enjoyment in it. Robert attempts to speak to her, but she replies, "speak not" (379). The stereotype of emotionally vulnerable, talkative women is placed here upon Robert Jordan, who attempts to converse with the silent and distant Maria.

While For Whom the Bell Tolls may contain elements of sexism, Hemingway veers from making the novel itself a sexist work. Confident and surely ahead of his time, Hemingway praises the untraditional female character of Pilar, giving her great power over the men. Maria, too, is given power, though in her sexuality, over Robert Jordan.