A key feature of a robust academic discipline is that its homegrown theories and investing in theory contribute to building good research. In the field of sport and social media research, the rigorous utilization of theory is one of the areas where the field is still facing “disciplinary pain.” In fact, the unique features of social media provide researchers in the sport research community with a valuable opportunity for proposing, testing, applying, critiquing, comparing, integrating, and expanding theories. In this commentary, the authors, based on their own experience (as researchers, readers, and reviewers of social media in sport), contend that reference resources are lacking on this topic to help young (or existing) researchers locate appropriate theories for their research. Hence, this work identifies, documents, and discusses the theories used, advanced, and developed in social media research for sport studies. Furthermore, a compilation is brought together of different theories from various disciplines that researchers in this community may consider for their future work.