1This study examined how practitioners who provide sport psychology support use 2 counselling principles and skills to develop practitioner-athlete relationships. Semi-structured 3 interviews were conducted with thirteen competent practitioners (Mean age = 41.2 ± 10.9 4 years old, five men, eight women). Thematic analysis revealed that the participants used a 5 range of counselling principles to develop practitioner-athlete relationships including: the 6 facilitative conditions, self-disclosure, counselling skills, the formation of working alliances, 7 and awareness of the unreal relationship. The participants also described using non-8 counselling strategies (e.g., gaining an understanding of the athlete's sporting environment) 9 to build relationships with their athletes. There was considerable variation between the 10 participants both in the training that they had received in counselling principles and skills, 11 and how they applied them. It was concluded that counselling principles and skills play a 12 significant role in the development of practitioner-athlete relationships.