In How to Understand Theatre Audiences , Kirsty Sedgman offers a bold rethinking of what it means to watch, experience, and make meaning from live performance. Drawing on theatre history, spectatorship theory, years of classroom teaching, and hands-on research practice, this book is a lively introduction to key debates in Theatre & Performance Studies, providing accessible explanations of ideas like semiotics, phenomenology, relational aesthetics, and the emancipated spectator. At the same time, it is also a manifesto for taking audiences seriously - not as a homogenous mass, but as diverse individuals whose experiences matter. Written in a clear, funny, and unapologetically opinionated style, the book is divided into two parts. 'Reviewing Audience Research' traces the long intellectual history of how audiences have been imagined, regulated, feared, and transformed over time. From Plato to participatory performance, and from unruly crowds to enforced silence, Sedgman dismantles the myth of the passive spectator and replaces it with a richly nuanced account of audiencing as an active, creative, and deeply political process. 'Doing Audience Research' then turns to the practical realities of empirical research: exploring methods from interviews, surveys, and focus groups to cognitive science techniques and creative participatory approaches and concluding by making a powerful case for listening seriously to what audiences say. Designed for students, scholars, practitioners, cultural professionals, and theatre fans alike, this book is an essential reading for anyone who wants to think better about spectatorship and the power of performance in a divided age.