Book excerpt: This book explores how the themes and insights of official Catholic Social Teaching (CST) and broader Catholic social thought might illuminate, and be illuminated by, a deeper engagement with the context of prisons. What resources might Catholic social thought bring to pastoral work in prisons? And what might listening to the prison context bring to Catholic social thought? The volume includes constructive proposals for the relationship between CST and prison ministry, as well as critical questions about the role and shortcomings of prisons, CST, and chaplaincy. It contains contributions by scholars and practitioners of theology, criminology, and prison chaplaincy from the UK, US, and Ireland, and reflects on the inextricable relationship of social action and pastoral care in the work of prison ministry.