Childhood studies place emphasis on children's agency, their ability to understand their own world and act upon it. Children actively participate in meaningful social interactions in both formal and informal settings. Considering recent large-scale migration in Ireland, it is vital to understand how children interact in an increasingly diverse world where they encounter cultural and religious difference. This article draws on a mixed-methods case study exploring religious education (RE) in community national schools (CNS), a new model of multi-denominational primary schools in Ireland. The results from focus groups with 10- to 12-year-old children show the role of agency in developing religious knowledge and forming inter-ethnic friendships, and the crucial role schools play in empowering pupils to interact with an increasingly diverse society.