In the interwar and immediate post-war years, the persistently high rates of emigration by young, single Irish women gave rise to worries over their moral and spiritual welfare. This was partly because of their assumed extreme vulnerability as women coming from rural loca- tions to the metropolises of England. It seems that the combination of their singleness and their gender was the prime reason for the concern evinced predominantly by the Roman Catholic Church, but also by lay organisations and the Irish governments. Multiple sources of danger for girls were perceived from their journey ‘across the water’ to their places of employment, from which they were in need of help and protection, if not prohibition. The majority of pronouncements on the topic were negative towards women, but no equivalent amount of concern was given to male migrants often of similar age and background and who also migrated as single persons. Thus, singleness was a gendered ‘problem’. Whilst studies of Irish female emigrants have focused on their experiences of being immigrants and their identity as white women who are in Bronwen Walter’s words ‘outsiders inside’, less attention has been paid to ways in which their single status became a marker of concern over morals and behaviour. Indeed, it is argued here that this was the particular reason why such moral- istic discourses existed. This article seeks to explore some of the complexities of the public and private voices engaged in the debates over whether single female emigration could be equated with sinful behaviour and the gendered implications of migrants’ marital status.