Introduction Increasing trust and confidence in vaccines is a global priority, as countries have grappled with delivering COVID-19 vaccines, maintaining routine childhood vaccination rates and introducing new vaccines. Community-based vaccine promotion interventions are commonly implemented, but effectiveness evidence is limited. In 2022, supported by the Australian Government and in partnership with Fiji’s Ministry of Health and UNICEF, we codesigned, delivered and comprehensively evaluated a vaccine education and communication training programme for health workers and community influencers to promote COVID-19 and routine immunisation. Methods The Vaccine Champions programme included three phases: (1) codesign with Fiji stakeholders; (2) vaccine education and communication training for Vaccine Champions and (3) support for Champions to deliver community vaccine discussion sessions over 6 months. The RE-AIM framework evaluation measured programme reach, effectiveness, adoption, implementation and maintenance. Mixed-methods data were collected through interviews, surveys and field notes, integrating qualitative and quantitative data to triangulate findings. Primary outcomes included Champions’ knowledge, communication self-efficacy, trust in COVID-19 vaccines, programme satisfaction and community members’ intention to vaccinate. Results We trained 35 Champions (27/35 female), including health workers, faith and community influencers. Half had a health background (17/35). Champions conducted 54 discussion sessions, reaching 1717 community members. Most Champions (22/35) conducted at least 1 session, with 16 running 3 or more. Champions who did not run sessions reported barriers like lack of confidence and competing duties. Training increased Champions’ communication self-efficacy and trust in COVID-19 vaccines. Community member intention to vaccinate increased from 41% (394/960) to 83% (822/991) before and after a session. The programme was well received with interest in continued engagement. Conclusion Training health workers and community Vaccine Champions can promote vaccine confidence. Programmes require government support and engagement for sustainability. Robust evaluation frameworks are needed to build the evidence base.