Background: Commitments to community participation are common in health policy, yet ways to maximise the input and impact of community representatives in health service delivery and care remain elusive, lack empirical evidence and are under-theorised. Methods. The role of Community Participation (CP) Coordinators involved in an Australian health service were examined in a triangulated multi-method, multi-site ethnographically informed three year study. Formal fieldwork involved observation of just over 42 hours of meetings together with informal interactions in the field with staff and community members and in-depth interviews and discussions with 10 Community Representatives, 19 staff and the seven CP Coordinators employed during the study period. Results: Four key roles that Community Participation Coordinators undertake to support and facilitate the action of community representatives operating within a health service were identified in our analysis: 1) Building skills and confidence; 2) Engaging them in agendas for action: 3) Helping them navigate and understand the health system; and 4) Advocating to staff. A fifth role of advocating externally to outside groups and building coalitions is suggested as important, but was not strongly represented in our data. Conclusions: This study offers a new model synthesising the key roles of coordinating and facilitating community participation in health services which may be transferable to other health service settings. Our findings call attention to the need for health services to employ a facilitator who can support, engage, navigate and advocate for community representative's participation and influence in health service policy and practice.