This article argues that engagement with religion is a key challenge for all leaders of schools in twenty-first-century multifaith societies. It outlines the historic and current context of the UK and the Republic of Ireland, and national and European policies that prioritise community cohesion in education. The functional and substantive roles of religion are considered as reflected in education, where they adjudicate power and shape values and behaviours. The article analyses data from nine schools in England, Wales and the Republic of Ireland to provide a snapshot of a range of leaders' philosophies, policies and practice in relation to religion. The preferential attention and resources given to the dominant community are evident in some cases. It is argued that, irrespective of whether a school is affiliated to a specific religion or not, school leaders have some freedom in positioning religion. Their influence significantly shapes how religion and/or secular values are understood and enacted. The article concludes by suggesting that policy at national and European level that emphasises shared identities and community cohesion masks the differential power and struggles between communities that cannot be resolved by anodyne exhortation. Rather, leaders need to be selected, trained and supported to recognise the centrality of belief in the lives of many of their learners and their families and to engage with the inevitability of ongoing disagreement and struggle.