Supporting refugee and migrant health has become a critical focus of healthcare policy. Developing and designing health literacy interventions that meet the needs of refugees and migrants is core to achieving this objective. This literature review sought to identify antecedents and consequences of health literacy among refugees and migrants during the first two years of the COVID-19 pandemic. We systematically searched nine electronic databases and numerous grey literature sources to identify studies published between December 2019 and March 2022. The antecedents (societal and environmental determinants, situational determinants, and personal determinants) and consequences of health literacy among refugees and migrants were mapped to a validated integrated health literacy model. Social and environmental determinants (n = 35) were the most reported antecedent influencing health literacy among refugees and migrants during the first two years of COVID-19. Language (n = 26) and culture (n = 16) were these determinants’ most frequently reported aspects. Situational determinants (n = 24) and personal determinants (n = 26) were less frequently identified factors influencing health literacy among refugees and migrants. Literacy (n = 11) and socioeconomic status (n = 8) were the most frequently reported aspects of personal determinants. Media use (n = 9) and family and peer influence (n = 7) were the most cited situational determinants reported. Refugees and migrants with higher levels of health literacy were more likely to use healthcare services, resulting in better health outcomes. The findings of this review reveal personal and situational factors that impacted health literacy among refugees and migrants during COVID-19 that require attention. However, the inadequate adaptation of health literacy interventions for linguistic and cultural diversity was a greater problem. Attention to this well-known aspect of public health preparedness and tailoring health literacy interventions to the needs of refugees and migrants during pandemics and other public health emergencies are paramount.