This paper introduces the Migrant Populations Equity Extension for Ontario’s Health Equity Impact Assessment (HEIA) initiatives. It provides a mechanism to address the needs of migrant populations, within a program and policy framework. Validation of an equity extension framework using community leaders and health practitioners engaged in HEIA workshops across Ontario. Participants assessed migrants’ health needs and discussed how to integrate these needs into health policy. The Migrant Populations Equity Extension’s framework assists decision makers assess relevant populations, collaborate with immigrant communities, improve policy development and mitigate unintended negative impacts of policy initiatives. The tool framework aims to build stakeholder capacity and improve their ability to conduct HEIAs while including migrant populations. The workshops engaged participants in equity discussions, enhanced their knowledge of migrant policy development and promoted HEIA tools in health decision-making. Prior to these workshops, many participants were unaware of the HEIA tool. The workshops informed the validation of the equity extension and support materials for training staff in government and public health. Ongoing research on policy implementation would be valuable. Public health practitioners and migrant communities can use the equity extension’s framework to support decision-making processes and address health inequities. This framework may improve policy development and reduce health inequities for Ontario’s diverse migrant populations. Many countries are now using health impact assessment and health equity frameworks. This migration population equity extension is an internationally unique framework that engages migrant communities.