Despite the immense challenges to mental health faced by refugees, research consistently finds that many nevertheless demonstrate remarkable resilience. However, a systematic account of the scientific literature on resilience among refugees is currently lacking. This paper aims to fill that gap by comprehensively reviewing research on protective and risk factors affecting refugees' resilience and mental health problems across four socio-ecological levels: individual, family, community, and society. We conducted a systematic search in the databases PsycINFO, Web of Science, and SocINDEX, as well as contacted topic experts to seek out unpublished manuscripts. This yielded 223 studies (171 quantitative, 52 qualitative), which were subjected to systematic content coding. We found consistent evidence for substantive risk factors, including traumatic experiences and gender at the individual level and postmigration stress and unemployment at the societal level. We found social support to be a clear protective factor at the family and community levels. We discuss these findings in the context of policy and intervention programs and make recommendations at different socio-ecological levels for supporting refugees' resilience.