Team members' successful execution of role responsibilities is critical to sport teams striving towards successful performance. The general purpose of this chapter is to review the literature on roles in sport. More specifically, a historical overview of the roles literature is first presented. This is followed by an outline of the structure of roles in sport teams and includes a conceptual model for the process of communicating and receiving role-related expectations. In addition, specific elements of role involvement (e.g., role ambiguity) are defined and discussed in terms of relevant research conducted in sport. Finally, implications and future directions for each role element are suggested, which highlight the importance and need for future research in this area.