While transgender and non-binary identities are increasingly visible, too many Christians have either maintained a fearful silence, or have attacked ‘transgenderism’ as a threat to Christian faith and practice. More serious theological reflection is needed, not least of all in the Roman Catholic tradition. Moreover, the Catholic context presents particular challenges that are relevant beyond the Catholic world, due to the Church’s widespread involvement in healthcare provision and education, and its traditions of thought around these activities. This volume considers the various questions to do with trans people in the life of the Church from an interdisciplinary, Catholic, ecumenical perspective, reaching out to academics, clergy and educated lay readers. It brings together perspectives from a variety of disciplines to provide a rigorous, wide-ranging engagement with these pressing issues; and includes a number of trans contributors, making their voices present in these discussions, which are about them, but from which they are often excluded. The first three chapters illustrate the development of Catholic thinking on transgender issues in recent decades. The second section of the book considers transgender identity from multiple perspectives: canon legal; legal; sociological, clinical; bioethical; and educational. The last two chapters of the second section shift the focus in the direction of theology and pastoral practice, themes that are explored by emerging theological scholars in the third section of the book.