This paper develops a novel approach to mapping diverse forms of participation and public engagement, using the example of the UK energy system. It builds on emerging systemic accounts of participation, which go beyond a focus on individual instances of participation, to gain an understanding of broader patterns and connections. Our approach, which forms part of an emerging family of methods that seek to map across multiple forms of public involvement in issues and systems, draws on systematic review methodology and a relational co-productionist conception of participation. The findings of a systematic mapping of public participation related to the UK energy system 2010–2015 are presented, comprising 258 cases in total. The mapping analysis reveals patterns as to the what (energy objects and issues), how (procedural formats) and who (publics) of energy participation in the UK, which go far beyond the conventionally assumed forms and sites of public participation around energy. Implications for how the dynamics of ‘whole system’ energy participation are represented and the role of approaches to mapping participation in governing energy transitions are considered.