Summary This dissertation studies the historical development of the Irish Catholic bildungsroman from James Joyce to Edna O ’Brien and John McGahern. Specifically, this study is focused on the construction of sexuality in this genre. The novels are therefore read in conjunction with those d iscourses of sexuality that were circulating in Irish Catholic culture between the First World W a r and the Second Vatican Council. The first chapter reconsiders the concentration on issues of public morality that characterised Irish Catholicism in the early twentieth century, and most acutely in the two decades after independence. In the second chapter, I discuss the epistemic shift in the understanding of modern sexuality that was occasioned by the historical emergence of sexology and psychoanalysis, before moving on to develop a close reading of Joyce’s A Po rtra it o f the A rtis t A s a Young Man (1916). The third chapter contains close readings of two novels by Kate O ’Brien, and locates O ’Brien’s narrative aesthetic, and the conception of sexuality that informs that aesthetic, within the broader historical context of Irish intellectual and political culture in the 1930s and 1940s. The next chapter analyses advice literature produced for Irish teenag ers between the 1940s and 1960s and I argue that this literature exemplifies a significant shift in Irish Catholic thinking on sexuality. The writings of Maura Laverty and Patrick Kavanagh are discussed in Chapter Five. Their rural bildung sromane are read as innovative permutations within the development of this genre and as complex interventions into mid-century debates about sexuality and Irish underdevelopment. Finally, Chapter Six offers close readings of Edna O 'B rie n ’s The Country Girls trilogy (1960-64) and John McGahern’s The Dark (1965). This chapter locates the distinctive narrative aesthetic and plotting of these bildung sromane within the history of the genre, and also reconsiders the critical consensus about the relationship between these novels and Irish modernisation.