This dissertation is a case study of the sanctoral cycle of the liturgical year in conflict and transformation, and utilizes a range of sources from Irish oral tradition to explore the liturgical phenomenon of the Irish patron day in the nineteenth and twentieth centuries. It is a constructive and corrective project that sheds light on obscured voices and devotional practices in Irish liturgical tradition and folklore, and raises important questions about nominal Christianization and secularization, and about the survival of loric power and even magical layers of Christian ritual in the face of encroaching anglicization and modernization. This dissertation poses and seeks to answer the following questions: what does it mean to celebrate the saints authentically, without obscuring the Paschal Mystery? How should we approach local traditions in the sanctoral cycle of the liturgical year? Why is the patron day such a resilient and malleable complex of rituals in the liturgical life of the church in Ireland? And why is it valuable to study oral traditions in the pursuit of liturgical research?Archival material from the National Folklore Collection and Dublin Diocesan Archive demonstrates the resiliency of the patron and its ability to contain and synthesize a range of characteristics endemic of indigenous Irish practice and the interpolation of Romanized customs in the nineteenth and twentieth centuries. I argue that the examples of living out and re-telling of relationships with and between the universal and local saints of the Irish calendar offer a in which to celebrate the feasts of the sanctoral cycle more authentically. In light of the recent efforts to revive the Irish language and Catholic liturgical participation in Ireland today, studying the Irish sanctoral cycle in folk narrative and popular practice through sources in the Irish language illuminate the richness of the Irish liturgical tradition.