This article highlights four key principles of cognitive behavior therapy (CBT) and proposes situations where these tenets would be relevant from an applied sport psychology perspective. To achieve this aim, a case study of an athlete with a dysfunctional perfectionist mindset is employed. We conclude with possible research directions in applied sport psychology informed by CBT. These recommendations include the need to further develop an evidence based formulation system and the relevance of building a repertoire of “evidence-based” behavioral experiments to improve practice.