Growing secularisation of the population and the arrival of new culturally and religiously diverse migrants are posing new challenges to schools in the Republic of Ireland (Ireland). These challenges are particularly acute in Irish primary schools, the majority of which are under Catholic patronage. Recent changes have necessitated an extensive consultation process about how to accommodate religious diversity and have resulted in some important policy changes. This article contributes to an ongoing debate about state-run denominational schools and the place of Religious Education in these. While set in the Irish context, the article is also relevant for educators and academics in other jurisdictions as it describes recent policy developments and steps taken in addressing cultural and religious diversity in schools.