There is a growing body of literature exploring the early development of sport psychology consultants (Collins, Evans-Jones, & O’Connor, 2013; Tod & Bond, 2010). However, there remains limited exploration of the longitudinal development of practitioners, an area which may provide important insights relevant for both training and education. Rønnestad and Skovolt’s (2003) sixstage practitioner development framework can be applied to the development of sport psychologists, each maturing at different rates and at times regressing through stages (Tod, 2007). Via six discrete published works this thesis details the author’s development as a practitioner over a 15-year period. Each publication is characterized by a stage of development, highlighting significant sources of influence, both professionally and personally. Study one details the author’s initial professional philosophy, grounded in the dominant western approach of CBT (Holt & Strean, 2001) and characterized as by a ‘layhelper’ and ‘beginning student’ phase. This philosophy shifted towards person-centered and briefer approaches as the author progressed through ‘advanced student’ and ‘novice professional’ phases, as detailed within studies two and three. Study four, an autoethnographic account, explored the challenges experienced by the author as a resident psychologist during a televised sporting event, characterized by the shift from ‘novice practitioner’ to ‘experienced practitioner’. Study 5 highlighted a shift in professional philosophy driven by an exploration of the philosophical writings underpinning brief therapeutic approaches. Finally, study six explored the development of a professional philosophy encompassing beliefs about the discipline as a whole and its role in supporting performers. Through a greater understanding of the journey from ‘lay helper’ to ‘senior practitioner’, the thesis highlights a range of areas for consideration by neophyte, mid-career and experienced practitioners. The thesis highlights the confusing and frustrating nature of development, highlighting that such feelings are natural and helpful to the development of skilled applied practitioners.