This introduction presents an overview of key concepts discussed in subsequent chapters of this book. The book is committed to 'being critical', with such commitment being achieved through all chapters problematizing taken for granted 'truths' to encourage researchers and/or practitioners to continue to step outside of the disciplinary and subcultural box. The book approaches the sport and physical activity subcultures and the participants within them using different critical perspectives, with the goal of expanding the critical cultural sport psychology (CSP) discourse. Further, it takes a critical approach as each is committed to creating safe and/or socially inclusive spaces for sport and physical activity participants in order to promote psychological well-being and an ethically and socially just sport psychology. The book is divided into three parts: sociocultural dimensions of inclusion/exclusion in sport, critiques of the medical model, sport culture and sport research, self-reflection and reflexivity in sport psychology practice and research.