SUMMARYBackgroundPandemic response and preparedness plans aim at mitigating the spread of infectious diseases and protecting public health, but migrants are often side-lined. Evidence amounted early that migrants are disproportionately affected by the COVID-19 pandemic and its consequences. However, synthesised evidence is lacking that quantifies the inequalities in infection risk and disease outcomes, or contextualises the consequences of pandemic measures and their underlying mechanisms.MethodsSystematic review searching 25 databases and grey literature (12/2019 to 11/2021). We considered empirical articles covering migrants, refugees, asylum-seekers, and internally displaced persons reporting SARS-CoV-2 cases, hospitalisation, ICU admission, mortality, COVID-19 vaccination rates or health consequences of pandemic measures. Random-effects meta-analysis of observational studies and qualitative analysis were performed for evidence synthesis. A Protocol was registered with PROSPERO (CRD42021296952).FindingsOut of 6956 studies, we included 241 in the review. For the quantitative studies (n=46), meta-analysis with over 40 million study participants showed that compared to non-migrants, migrants have an elevated risk of infection (RR = 2·33; 95%-CI: 1·88-2·89) but similar risk for hospitalisation (RR = 1·05; 0·80-1·37), while the likelihood of ICU admission was higher (RR = 1·36; 1·04-1·78). Among those hospitalised, migrants had a lower risk of mortality (RR = 0·47; 0·30-0·73), while their population-based excess mortality tended to be higher (RR = 1·31; 0·95-1·80). The qualitative synthesis (n=44) highlighted the complex interplay of social and COVID-19-related factors at different levels. This involved increased exposure, risk, and impact of pandemic measures that compromised the health of migrants.InterpretationEven in the advanced stages of the pandemic, migrants faced higher infection risks and disproportionately suffered from the consequences of COVID-19 disease, including deaths. Population-level interventions in future health emergencies must better consider socio-economic, structural and community-level exposures to mitigate risks among migrants and enhance health information systems, to close coverage gaps in migrant groups.FundingNone.