James Ellroy is an eccentric and divisive popular novelist. Since the publication of his first novel Brown’s Requiem in 1981, Ellroy’s outré ‘Demon Dog’ persona and his highly stylised, often pornographically voyeuristic and violent crime novels have continued to polarise both public and academic opinion. This study considers Ellroy’s status as an historical novelist, critically evaluating the significance and function of voyeurism in his two collections of epic noir fiction The L.A. Quartet and The Underworld U.S.A. Trilogy. Using a combination of psychoanalysis, postmodern and cultural theory, it argues that Ellroy’s fiction traces the development of the voyeur from a deviant and perverse ‘peeping tom’ into a recognisable, contemporary ‘social type’, a paranoid and obsessive viewer who is a product of the decentred and hallucinatory, ‘cinematic’ world that he inhabits. In particular, it identifies a recurring pattern of ‘ocularcentric crisis’ in Ellroy’s texts, as characters become continually unable to understand or interpret through vision. Alongside a thematic analysis of obsessive watching, this project also suggests that Ellroy’s works - particularly his later novels - are themselves voyeuristic, implicating the reader in these broader narrative patterns of both visual and epistemophilic obsession. While principally a study on Ellroy’s work, this thesis also attempts to situate his texts within the broader contexts of both the contemporary historical novel and our pervasive ‘culture of voyeurism’. This thesis will therefore be of interest not only to Ellroy critics and readers, but also to scholars of both contemporary fiction and contemporary cultural studies.