Bibliographical recoveries have decisively challenged older views about Victorian Ireland’s supposed failure to produce fiction, but the perception that the Irish novel was in many ways anomalous remains a hallmark of scholarship on the period, regardless of whether that anomaly is deplored or celebrated. This chapter reviews the main theories that have used sociological, cultural, ideological and economic factors to analyse the marginality and generic deviancy of Irish fiction, where realism is often overshadowed by allegorical and Gothic strains. It then suggests that the aesthetic standards that are used to assess the idiosyncrasies of Irish Victorian novels remain implicitly indebted to influential but questionable definitions of realism in Anglo-American literary criticism. While acknowledging some of Irish fiction’s differences from the realist canon, this chapter also highlights their mutual imbrication by tracing Irish influences and inspirations in the works of various English and French realists, and the latter’s roles in Irish literary history. Ireland’s paradoxical blend of peripherality and proximity to the centres of nineteenth-century European cultural production is here used to recontextualise terms like realism, allegory and Gothic, and to emphasise their porousness not just in Irish writing, but in the very canon from which Irish Victorian fiction is too often segregated.