In early phases of the COVID-19 pandemic in Singapore, Risk Communication and Community Engagement (RCCE) with large, diverse communities of migrant workers living in high-density accommodation was slow to develop. By August 2020, Singapore had reported 55,661 cases of COVID-19, with migrant workers comprising 94.6% of the cases. A system of RCCE among migrant worker communities in Singapore was developed to maximize synergy in RCCE. Proactive stakeholder engagement and participatory approaches with affected communities were key to effective dissemination of scientific information about COVID-19 and its prevention.