Samuel Spade is a private detective and his ostensible immorality, disregard for authority, self-interest, and even his looks—he is described as looking “pleasantly like a blonde satan”—make him an antihero (5). Spade also embodies a romanticized version of the time’s idea of traditional masculinity: He is physically strong, stoic, logical, desirable to women, terse, and able to compartmentalize his emotions. The novel valorizes this form of masculinity through Spade and perpetuates homophobia by contrasting it with the other, more effeminate male characters in the novel, such Cairo and Wilmer. His relationship with O’Shaughnessy forms the secondary tension in the novel, as both of their feelings are difficult to parse due to lying and manipulation. Spade is aware of the way that O’Shaughnessy has used men in the past, and his reluctance to fall into this trap makes it impossible for him to trust her. At the end of the novel, while the mystery of the Maltese falcon is closed, the question of Spade’s and O’Shaughnessy’s true feelings toward one another remains unresolved, suggesting that some truths can never be fully knowable.

At the beginning of the novel, Spade accepts payment from all parties involved, and he strips O’Shaughnessy down to her last dollar despite her pleas for help.