“Athlete activism” has received a significant amount of scholarly attention in recent years. In this brief, introductory chapter, I outline how athletes at the elite level of sport across the Western world (such as Colin Kaepernick, Megan Rapinoe, and Marcus Rashford), as well as athletes at sub-elite levels of sport are increasingly engaging in various forms of activism. I then outline the approach adopted by the book, including an acknowledgment that this text only includes an analysis of athlete activism in the Western world, before providing a short synopsis for each of the book’s 17 chapters.