Stephen Dedalus is the novel's protagonist, although readers' sympathies may not always lie with him. From early childhood he perceives the world in a highly personalized and sensitive way. As he grows older this peculiarity and sensitivity will prove problematic; it will restrain him as a student, particularly as a student bound for the priesthood. The novel shows Stephen's grappling with the warring impulses within himself: the impulse to create and experience life at its fullest versus the impulse to lead a virtuous life as a model for others.
Simon Dedalus is the affectionate but dissolute patriarch of Stephen's family. He is plagued by drinking problems, discipline problems, and emotional problems. His inability to entirely master these issues is a source of stress and instability for his family. Simon and Stephen are close, but as Stephen grows older and must assume more family responsibility due to his father's irresponsibility, their relationship becomes one of strained tolerance.
Mary Dedalus is portrayed in fairly broad strokes in the novel. She takes care of Stephen, and early on he notes she has a nicer smell than his father. Mary also attempts to discipline Stephen when his father is absent (either physically or emotionally). In the first chapter she reprimands Stephen for being too forward with a Protestant female neighbor; much later in the novel, she scolds Stephen for spending money from an academic prize too wildly. Still later she bemoans Stephen's abandonment of the priesthood.
Stephen has a deep bond with Cranly. The two classmates have conversations Stephen would never have with others because Stephen feels Cranly can understand him. As a result, Cranly learns more about Stephen than others do; he is also more receptive to Stephen's eccentricity than others are.