Social participation plays a key role in the integration of refugees and asylum seekers into their host societies, and is also closely tied to the mental health of those populations. The aim of this scoping review was to study how the concept of social participation is described in empirical research, and how it is associated with mental health outcomes. Methods: In total, 64 studies were identified through searches in PubMed, PsycInfo, and Sociological Abstracts. These studies describe various forms of social participation among refugees and asylum seekers, and 33 of them also addressed various forms of mental health outcomes. Results: The identified studies described forms and conditions of social participation—both in the host country and transnationally—that could be synthesized into three broad dimensions: (1) Regulatory frameworks, conditions and initiatives; (2) Established societal organizations and social structures; and (3) Community organized groups. Each of these consisted of several sub-domains. The identified dimensions of social participation were also associated with psychosocial well-being and decreased psychological distress. Conclusions: There is a need for policies to enable and support the participation of refugees and asylum seekers in various dimensions of social structures in host societies. Social participation enhances resilience, re-establishes social lives, and acts as a protective factor against poor mental health outcomes. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.