Diamond is the novel’s main character—a young boy of uncertain age who undergoes many strange experiences with the North Wind. Diamond begins At the Back of the North Wind as a young, silly boy who goes along with the desires of others. He follows adult’s logic with few questions and acts more as a companion than a leader. He is described as having a “pale face and fair hair” as well as blue eyes (197). It also becomes evident that Diamond is sickly: His mother is keen to keep him indoors, and when visiting his aunt in Sandwich, he succumbs to an illness that makes him sleep for a week. It is no coincidence that Diamond’s lapses into illness coincide with visits by the North Wind. She offers him a way of escaping the struggles he finds himself in, but she also symbolizes the looming possibility of death.

As the novel progresses, Diamond maintains his gentle demeanor but also establishes his own desires and intentions. He consistently chooses to help others, even though not doing so would be an easier option. For example, he is a devoted brother to his siblings, and his mother claims that he is “as good to your mother as if you were a girl—nursing the baby, toasting the bread, and sweeping up the hearth” (85).