Criticism of J.K. Rowling’s Harry Potter series has maintained that its popularity stems from a well-marketed, repetitive and simple structure. However, this essay considers that this success derives from recognizable mythological heroic structures. The essay traces the protagonist’s development from the perspective of two different theories that contrast and complement each other in various ways, Otto Rank’s theory of the myth of the birth of the hero and Joseph Campbell’s theory of the monomyth. Campbell and Rank both hypothesize that hero myths are repetitive because they emerge from the subconscious of human kind. It can be seen in the tracing of the heroic development in Harry Potter that— although various aspects and features in the hero’s journey are followed in the narrative — the series does not strictly fit these theories. The result is a combination of different features from both theories, which modernizes the heroic myth that has pervaded human culture and history since time immemorial.