Sport is deemed by many researchers and practitioners as a favourable context to foster positive youth development (PYD), including the acquisition of life skills (Petitpas et al., 2005). However, researchers have cautioned for vigilance before assuming with assurance that sport leads to positive developmental outcomes (Coakley, 2011). Consequently, it is important to understand how sport leaders can facilitate the development and transfer of life skills. In the context of high school sport in Canada, teacher-coaches are considered essential adults in the delivery of school sport programs. Using Pierce et al.’s (2017) life skills transfer model, the present thesis explored the contextual and psychological factors influencing the development and transfer of life skills. An intervention was designed, using action research principles, with two high school teacher-coaches. Data were collected via teacher-coach pre- and post-intervention interviews, as well as student-athlete post-intervention interviews (i.e., five student-athletes per teacher-coach). Further, data were gathered through observation, and audio recording of each life skill implementation, as well as a researcher reflective journal. The results indicated that teacher-coaches played an important role in influencing contextual and psychological factors, in both the learning and the transfer context, which shaped student-athletes’ life skills development and transfer. The study has practical implications for coach education programs, suggesting the benefits of on the ground support to provide coaches and teacher-coaches with the necessary tools to promote PYD.