South Korean cinema has enjoyed a rise in academic attention since the turn of the twenty-first century. That said, the way in which the vibrant and tumultuous history of the Korean peninsula throughout the twentieth century affected the development and evolution of film genre has yet to be examined in-depth. This thesis therefore seeks to establish histories of Korean film genres by examining the on-screen shifts and transitions of genre. Focusing on three genres - melodrama, action, and horror - this thesis illuminates the complex relationships and interactions occurring within the East Asian region, showing how Korean cinema has interacted with the genre cinema of its geographic neighbours. At the same time this thesis excavates the pre-cinematic histories of these genres in an attempt to establish genealogical evidence of genre form and content as found in folklore, theatre, and other traditional narrative media or performance. In doing so, this thesis attempts to challenge the assumed universality of genre terminology by exploring the degree to which such terms are able to map onto cinemas fuelled by cultural traditions and histories which are largely disparate from the Western films that historically informed the notions and understandings of particular genres. As such, this thesis hopes to discuss Korean cinema through an investigation into genre which places emphasis on Korea's own cinematic and pre-cinematic histories.