Conducting behavioural research in areas of environmental sustainability; health and wellbeing; community resilience; and economic development should be informed by meaningful public engagement and stakeholder involvement (PESI) approaches to ensure cross-pollination of transdisciplinary views and ideas – transcending conventional siloes and sectoral boundaries. However, employing effective and appropriate PESI approaches that uphold the principles of equality, diversity, inclusion, and intersectionality (EDII) in behavioural research remains a challenge for researchers and practitioners. The main aim of this scoping review is to understand how PESI approaches and EDII principles are applied in behavioural research projects conducted in the UK. Evidence from this review will be used to inform the development of guidance materials that will help improve the capability of researchers and practitioners in using PESI approaches and EDII principles in behavioural research.