Abstract: This thesis focuses on young Christians’, Jews’ and Muslims’ experiences of interfaith work in the UK and what impact(s) being involved in interfaith might have on their religious, social, ethical and political identities. It is situated in a growing academic and policy interest in interfaith work as a means to build cohesive communities, mitigate tension and conflicts, and encourage active citizenship. It also engages with still under-explored questions around how young people active in interfaith work are affected by this activism. The aim is not only to understand how and why young people from different religions are involved in interfaith work, but also the impact being involved in interfaith work might have on young people’s identities and sense of belonging. Focusing on the biographical accounts of young Christians, Jews and Muslims involved in three different interfaith organisations in UK, the thesis explores how the young people have become interested in interfaith work; the relationships, messages and contexts that have been important in forging this interest and activism; what interfaith work means to them socially, theologically, ethically and politically; and the challenges they have experienced with this form of faith-based engagement. Drawing on Kate Tilleczek’s ‘complex cultural nesting approach’, this thesis attends to the young people’s complex personal experiences of interfaith work and the different social actors, contexts and frameworks that have been important in forming this interest. The thesis shows that, to understand young people’s interfaith work, we need a multidimensional approach that considers social and theological dimensions in young people’s lives; look at how interfaith work is a means to fulfil social and political goals, but also forms of theological commitment; and explore how challenges facing interfaith work inform young people’s experiences in different ways, particularly theological, social and political tension in relation to interfaith space, religious congregations and British society at large.