As the cult of saints became increasingly important to the Christian religion during the latter stages of the Roman Empire, so too the veneration of relics became a central element of Christian piety. The urge to physically touch, kiss, or just be in the presence of saintly remains survives to this day. The estimated 250,000 British and Irish visitors to the relics of St Anthony of Padua in 2013, and the millions that attended the tours of St Thérèse’s relics to Ireland, in 2001, 2009, and 2012, offers us an insight into the enduring power with which saintly remains have been invested in Ireland.1 Indeed, the widespread media coverage of the discovery by Irish police in April 2018 of the heart of St Laurence O’Toole, stolen from Dublin’s Christ Church Cathedral six years earlier, indicates an ongoing fascination with the cult of relics. This chapter explores how and why the cult of relics became a key element in the functioning of the Christian church in early medieval Ireland, as elsewhere, and in the Church’s interaction with society. Furthermore, it will question whether it was the Church’s control of the cult that ensures its longevity or whether the Church simply tapped into an essential part of human existence. Through an examination of the veneration of relics in Ireland, this study will shed light on the lasting appeal of the cult and what implications this has for our perceptions of religion in our modern, secular, global society.