Athletes attract significant interest from the public which can be leveraged to build highly distinguishable athlete brands. With the inception of social media platforms, athletes have been provided an opportunity to promote their personal brands and attract engagement from consumers. This chapter provides insight into social media branding with a focus on high-performance athletes including professional, Olympic/Paralympic, and student-athletes. The chapter begins with an overview of athletes as brands by defining the concept of a brand in the sport landscape. The role social media has played in developing athlete brands is then presented, followed by an overview of theories and frameworks applied to athletes and social media branding research. The platforms that have been predominately used in empirical research are also explored, revealing Instagram and Twitter as the two main platforms used for athlete branding. This chapter also highlights the research areas that are well established and others that are emerging by outlining directions for future research. These areas include the challenges and opportunities of COVID-19, athlete philanthropy and activism, athletes as role models and influencers, challenges of social media branding, and emerging platforms and features that may shape the future of athlete social media branding.