Refugees within the post-migration context experience higher rates of mental health symptoms due to a variety of pre- and post-migration factors. However, there is a lack of research in understanding best practices in culturally grounded interventions aimed at improving well-being outcomes. Recent research shows group interventions are a potential pathway to mental health treatment for refugees. This systematic review aimed to (1) assess best practices among group-based interventions within the refugee context, (2) provide literature-informed guidance on best practices within group-based interventions for this population, and (3) examine the impact of group-based interventions on the mental health outcomes of adult refugees in the post-migration context in high-income countries. A systematic literature search was conducted using Academic Search Complete, Social Work Abstracts, and PsycINFO. A total of 2,243 studies were identified, with 19 meeting the inclusion criteria to be from a peer-reviewed journal article; be published from 2003 to 2023; be written in English; have a study population of refugees in the post-resettlement context in a high-income country; include a group-based intervention model; and be quantitative or mixed methods. Results demonstrated that group-based interventions improve mental health symptoms, including post-traumatic stress disorder, depression, and anxiety. Studies varied on their use of culturally grounded mechanisms in developing and implementing interventions. Future research is needed to understand the longitudinal impacts of group-based interventions on mental health and better support current practices to facilitate access to intervention implementation.