The Children and Families Act (Department for Education [DfE], 2014) requires educational psychologists (EPs) to work with children and young people with special educational needs and disabilities from birth to 25. EPs have had to develop or expand their practice to meet the needs of the post-16 population. Research on transition from compulsory education to further education, employment or training highlights significant variability in practice. In paper one, a systematic literature review was undertaken to explore the potential role and contributions of EPs in supporting post-school transition to further education, employment or training. Seven studies met inclusion criteria. The second paper comprises of an Action Research study which explored the views of a group of EPs on supporting the mental health of post-16 students in further education. A series of four focus groups, informed by Appreciative Inquiry, were facilitated in order to explore and highlight areas for post-16 professional practice development. Participants were six members of a local authority (LA) educational psychology service (EPS). Analysis involved collaborative group discussion and clarification, researcher reflection and thematic analysis. The research highlights the potential contributions of EPs within post-16 work, at individual, group and systemic levels. The findings need to be situated within the context of local authority structures and austerity measures, which may act as a barrier to the future commissioning of post-16 EP practice. Finally, paper three considers how to effectively disseminate the findings of this thesis, providing a systematic and detailed strategy for propagating implications at the research site, local, regional and national levels.