Aim: In the UK the change from a one-year Masterâ€™s to a three-year doctoral training programme has provided extended opportunities and challenges for trainee educational psychologists in developing their practitioner skills and professional role. Supervision is a key foundation for supporting trainees in this process. This paper provides an analysis of the supervision experiences of trainee educational psychologists informed by developmental theories of supervision. Method: In order to explore the developmental experiences of trainee educational psychologists across the three years of training, focus groups were undertaken with each year group of trainee educational psychologists at four initial educational psychology training programme sites. These 12 focus groups were analysed using thematic analysis. Findings: Five key themes relating to the development of practitioner skills were identified; developing professional learning and professional role; responsiveness to developmental learning needs; sensitive management of emotional aspects of learning; developing critical analysis of professional work and metaanalysis of professional activity and professional role. Limitations: There is a need for longitudinal research into developmental models of supervision and their application to EP training specifically. Conclusions: The five themes provide some support for the utility of developmental models of supervision in informing the future development of UK educational psychology training.