BACKGROUND: Public mental health (PMH) is a global challenge and a UK priority area for action. However, to progress, practitioners require a stronger evidence base regarding the effectiveness of approaches, particularly regarding promotion and prevention through community-centred interventions. In addition, policy-makers need to understand what is being delivered, particularly in areas of high need, to identify promising practices or gaps in PMH provision. Finally, and importantly, the public need better information regarding what approaches and services are available to them. We report a protocol designed to (1) identify the types of community-centred interventions used in purposively selected diverse geographical areas of England to improve PMH outcomes and (2) describe the type, target population, content and outcome measures of each intervention. METHODS AND ANALYSIS: Five local authority areas of England were selected based on either high social deprivation or differing ethnic population statistics and geographical locations. Community-centred interventions in each area will be identified through: (1) desk-based data capture from standardised searches of publicly-available information (eg, policy, strategy and intervention advertising), (2) established professional networks and service contacts, (3) chain-referral sampling of individuals involved in local mental health promotion and prevention and (4) peer researchers, who will use their personal experience and local knowledge to help identify potentially relevant organisations. Data on the key features of the interventions will be extracted from individuals either by structured interviews or by electronic questionnaires with information regarding the intervention(s) of which they have knowledge. Initial data analysis will involve tabulating descriptive information and grouping interventions according to intervention type, target population, risk/protective factor and intended primary outcome. A descriptive comparison will be made between selected geographical areas. ETHICS AND DISSEMINATION: Ethical approval was obtained from Durham University's Department of Sport and Exercise Sciences Research Ethics Committee. We plan to disseminate our findings at relevant conferences, meetings and through peer-reviewed journals. We also plan to disseminate to the public and intervention providers through social media and/or newsletters.