The main objective of this chapter is to provide an overview of the self-talk literature in sport psychology, in particular with regard to the links between self-talk and performance. Definitions and conceptualizations are discussed, and measurement issues are presented. The main research questions that have been addressed and the research paradigms that have been adopted to address these questions are then outlined. The content of athletes’ self-talk and the use of self-talk strategies are then described, and the factors shaping and influencing self-talk are discussed. The main body of the chapter focuses on the relationship between self-talk and performance, with particular emphasis placed on research advances regarding the mechanisms that may explain the facilitating effects of self-talk on performance. A brief look at performance-related self-talk research within other psychology domains is then presented. Finally, applied recommendations and future research directions are discussed.