This book brings together chapters from leading scholars and researchers who have developed innovative theories and methods of Qualitative Secondary Analysis (QSA). Combined, the chapters provide a comprehensive introduction to the range of epistemological, ethical and pragmatic aspects of QSA. This book especially addresses researchers new to debates on qualitative data re-use. It aims to provide both depth of understanding of the key methodological challenges QSA entails, and also offer practical tools and strategies you can apply in your own research practice. To give a broad overview of the general methodological terrain of questions on QSA, our Introduction charts the rise of debates on Qualitative Secondary Analysis (QSA). We show how QSA has emerged as a distinct methodological approach in tandem with changes in the research data landscape. Our discussion briefly introduces the main critiques and challenges of QSA and we signpost to the relevant chapters where such questions are addressed in depth. As with all other chapters in this volume, we include pedagogical resources at the conclusion of this chapter along with references.