Concerns relating to the management of externalising and internalising behaviour are prevalent within UK educational policy and practice and represent a key domain for Educational Psychologist (EP) support. EP practice has been subject to change over time, following shifts in legislative approaches to managing behaviour in schools and changes to the contexts and systems within which EPs work, such as increased service trading. A systematic literature review (SLR) sought to represent EP behaviour practices within the existing literature. 12 papers, published between 2000-2017 were identified using a PRISMA framework and evaluated for methodological quality, appropriateness and relevance of focus. An empirical investigation, utilising the Research and Development in Organisations (RADIO) model within a single-case design, was also conducted within a north-west local authority educational psychology service. A focus group with 5 EPs and the Principal EP (PEP), and an interview with the PEP, were carried out and thematically analysed. The SLR identified a range of behavioural practices at individual, group and organisational levels, exemplifying the core functions of the EP role. Single and integrated psychological paradigms were applied, within relational and social constructionist approaches. The empirical investigation identified a range of behavioural practices, and underlying psychological paradigms, alongside ideas for future developments in behaviour service delivery and the possible facilitators and barriers to achieving this were considered. Reflections on the utility and experience of EP involvement in action research were also facilitated, with content analysis findings presented. Links to theory and practice, and implications for future research are considered, including empirical investigation of EP practice within local contexts. The application of psychology within local contexts and service development processes, are also considered. Finally, following an exploration of the concepts of evidence-based practice and practice-based evidence, and their implications for practitioner psychologists, a dissemination strategy for sharing findings with participants and the wider EP community is proposed.