This thesis investigates the experience of Polish migrants in Ireland and how, if at all, spirituality or the church figure in terms of social and spiritual support. Drawing on data from in-depth interviews with Polish migrants and clergy, participant observation and documentary materials and guided by theories of religion as resource, achieved identity, and transnational entity, I identify four major empirical findings. First, religion is not a significant factor motivating the migration of Polish migrants to Ireland and instead economic and social factors predominate. Second, there is considerable variation in migrants’ religious beliefs and practices, ranging from migrants who strongly identify with Catholicism to migrants who dis-identify with Catholic identity. Third, some Polish migrants rely on the church for various resources while others do not, depending on factors such as social networks, transnational ties and religious identity. I find that religion matters more as a marker of ethnic identity and social service resource than spirituality. In addition, the Polish chaplaincy draws on transnational resources to help some migrants maintain their religious identity and connection to Poland. Migrants, in turn, mobilise transnational networks to further support the preservation of ties to their homeland. Theoretically, this thesis gives weight to the perspective that religion and religious institutions operate transnationally, yet migrants’ relationship with religion is constantly negotiated and adapted depending on their time and context specific situations, some migrants ‘opt in or out’ of religion when ‘necessary’.